COMEDK Practice Set 6
Original COMEDK-style Set 6 (paper-pattern aligned) with 180 questions: 60 Mathematics, 60 Physics, and 60 Chemistry at balanced moderate level.
Exam Pattern & Rules
Negative Marking: No negative marking
Note: 60 MCQs each in Physics, Chemistry, and Mathematics.
Practice Set Details
COMEDK Practice Set 6: all 180 questions with answers
Try each question first, then open “Show answer” to check the correct option and explanation.
Q1.If roots of x² − 5x + 6 = 0 are α and β, value of α·β is:
- A.5
- B.8
- C.4
- D.6
Show answer
Correct answer: D. 6
For x² − Sx + P = 0, product of roots is P.
Q2.Sum of first 12 terms of AP with a=5, d=2 is:
- A.180
- B.84
- C.192
- D.204
Show answer
Correct answer: C. 192
Use Sn = n/2 * [2a + (n-1)d].
Q3.Value of 6C3 is:
- A.18
- B.20
- C.21
- D.19
Show answer
Correct answer: B. 20
Use nCr = n!/(r!(n-r)!).
Q4.If y = x^3, then dy/dx at x=2 equals:
- A.12
- B.8
- C.6
- D.14
Show answer
Correct answer: A. 12
Derivative of x^n is n*x^(n-1).
Q5.Integral from 0 to 3 of 3x dx is:
- A.16.5
- B.9
- C.10.5
- D.13.5
Show answer
Correct answer: D. 13.5
Integral of kx is (k/2)x^2 and then apply limits.
Q6.Area of circle of radius 5 is:
- A.5pi
- B.30pi
- C.25pi
- D.10pi
Show answer
Correct answer: C. 25pi
Area = pi*r^2.
Q7.If slopes are m1=4 and m2=-1, then m1*m2 is:
- A.-6
- B.-4
- C.3
- D.5
Show answer
Correct answer: B. -4
Multiply the two slopes directly.
Q8.Determinant of matrix [[2, 1], [1, 6]] is:
- A.11
- B.13
- C.10
- D.14
Show answer
Correct answer: A. 11
For 2x2 matrix, determinant = ad - bc.
Q9.Value of 8P3 is:
- A.56
- B.342
- C.330
- D.336
Show answer
Correct answer: D. 336
nPr = n!/(n-r)!.
Q10.Two balls are drawn without replacement from a bag having 4 red and 7 blue balls. Probability that both are red is:
- A.12/11
- B.42/110
- C.12/110
- D.4/11
Show answer
Correct answer: C. 12/110
Use P(R1 and R2) = (red/total)*((red-1)/(total-1)).
Q11.Modulus of complex number 6 + 4i is:
- A.24
- B.7.21
- C.10
- D.2
Show answer
Correct answer: B. 7.21
|a+bi| = sqrt(a^2 + b^2).
Q12.Dot product of vectors (1, 2) and (3, 3) is:
- A.9
- B.-3
- C.11
- D.7
Show answer
Correct answer: A. 9
For 2D vectors, dot product is x1x2 + y1y2.
Q13.Value of sin²θ + cos²θ is:
- A.0
- B.2
- C.sin 2θ
- D.1
Show answer
Correct answer: D. 1
Fundamental Pythagorean identity.
Q14.If log10(x) = 4, then x equals:
- A.40
- B.1000
- C.10000
- D.4
Show answer
Correct answer: C. 10000
From log10(x)=p, x=10^p.
Q15.Limit of (x^2 - 16)/(x - 4) as x tends to 4 is:
- A.9
- B.8
- C.4
- D.13
Show answer
Correct answer: B. 8
Factor numerator: (x-n)(x+n), cancel and substitute x=n.
Q16.If roots of x² − 8x + 15 = 0 are α and β, value of α·β is:
- A.15
- B.8
- C.17
- D.13
Show answer
Correct answer: A. 15
For x² − Sx + P = 0, product of roots is P.
Q17.Sum of first 12 terms of AP with a=4, d=3 is:
- A.258
- B.234
- C.84
- D.246
Show answer
Correct answer: D. 246
Use Sn = n/2 * [2a + (n-1)d].
Q18.Value of 7C2 is:
- A.20
- B.14
- C.21
- D.22
Show answer
Correct answer: C. 21
Use nCr = n!/(r!(n-r)!).
Q19.If y = x^4, then dy/dx at x=2 equals:
- A.34
- B.32
- C.16
- D.8
Show answer
Correct answer: B. 32
Derivative of x^n is n*x^(n-1).
Q20.Integral from 0 to 3 of 2x dx is:
- A.9
- B.11
- C.6
- D.7
Show answer
Correct answer: A. 9
Integral of kx is (k/2)x^2 and then apply limits.
Q21.Area of circle of radius 6 is:
- A.12pi
- B.6pi
- C.42pi
- D.36pi
Show answer
Correct answer: D. 36pi
Area = pi*r^2.
Q22.If slopes are m1=3 and m2=-2, then m1*m2 is:
- A.5
- B.-8
- C.-6
- D.1
Show answer
Correct answer: C. -6
Multiply the two slopes directly.
Q23.Determinant of matrix [[5, 2], [2, 7]] is:
- A.34
- B.31
- C.39
- D.16
Show answer
Correct answer: B. 31
For 2x2 matrix, determinant = ad - bc.
Q24.Value of 7P3 is:
- A.210
- B.35
- C.216
- D.204
Show answer
Correct answer: A. 210
nPr = n!/(n-r)!.
Q25.Two balls are drawn without replacement from a bag having 5 red and 6 blue balls. Probability that both are red is:
- A.5/11
- B.20/11
- C.30/110
- D.20/110
Show answer
Correct answer: D. 20/110
Use P(R1 and R2) = (red/total)*((red-1)/(total-1)).
Q26.Modulus of complex number 5 + 5i is:
- A.0
- B.25
- C.7.07
- D.10
Show answer
Correct answer: C. 7.07
|a+bi| = sqrt(a^2 + b^2).
Q27.Dot product of vectors (2, 5) and (4, 4) is:
- A.26
- B.28
- C.-12
- D.30
Show answer
Correct answer: B. 28
For 2D vectors, dot product is x1x2 + y1y2.
Q28.Value of 1 + tan²θ is:
- A.sec²θ
- B.csc²θ
- C.1
- D.cos²θ
Show answer
Correct answer: A. sec²θ
1 + tan²θ = sec²θ.
Q29.If log10(x) = 3, then x equals:
- A.3
- B.30
- C.100
- D.1000
Show answer
Correct answer: D. 1000
From log10(x)=p, x=10^p.
Q30.Limit of (x^2 - 9)/(x - 3) as x tends to 3 is:
- A.10
- B.7
- C.6
- D.3
Show answer
Correct answer: C. 6
Factor numerator: (x-n)(x+n), cancel and substitute x=n.
Q31.If roots of x² − 11x + 28 = 0 are α and β, value of α·β is:
- A.26
- B.28
- C.11
- D.30
Show answer
Correct answer: B. 28
For x² − Sx + P = 0, product of roots is P.
Q32.Sum of first 12 terms of AP with a=3, d=4 is:
- A.300
- B.312
- C.288
- D.84
Show answer
Correct answer: A. 300
Use Sn = n/2 * [2a + (n-1)d].
Q33.Value of 8C3 is:
- A.57
- B.55
- C.24
- D.56
Show answer
Correct answer: D. 56
Use nCr = n!/(r!(n-r)!).
Q34.If y = x^5, then dy/dx at x=2 equals:
- A.10
- B.82
- C.80
- D.32
Show answer
Correct answer: C. 80
Derivative of x^n is n*x^(n-1).
Q35.Integral from 0 to 3 of 5x dx is:
- A.17.5
- B.22.5
- C.27.5
- D.15
Show answer
Correct answer: B. 22.5
Integral of kx is (k/2)x^2 and then apply limits.
Q36.Area of circle of radius 7 is:
- A.49pi
- B.14pi
- C.7pi
- D.56pi
Show answer
Correct answer: A. 49pi
Area = pi*r^2.
Q37.If slopes are m1=2 and m2=-3, then m1*m2 is:
- A.-1
- B.5
- C.-8
- D.-6
Show answer
Correct answer: D. -6
Multiply the two slopes directly.
Q38.Determinant of matrix [[4, 3], [1, 4]] is:
- A.12
- B.16
- C.13
- D.19
Show answer
Correct answer: C. 13
For 2x2 matrix, determinant = ad - bc.
Q39.Value of 10P3 is:
- A.714
- B.720
- C.120
- D.726
Show answer
Correct answer: B. 720
nPr = n!/(n-r)!.
Q40.Two balls are drawn without replacement from a bag having 6 red and 5 blue balls. Probability that both are red is:
- A.30/110
- B.6/11
- C.30/11
- D.20/110
Show answer
Correct answer: A. 30/110
Use P(R1 and R2) = (red/total)*((red-1)/(total-1)).
Q41.Modulus of complex number 4 + 6i is:
- A.10
- B.2
- C.24
- D.7.21
Show answer
Correct answer: D. 7.21
|a+bi| = sqrt(a^2 + b^2).
Q42.Dot product of vectors (3, 4) and (3, 1) is:
- A.15
- B.11
- C.13
- D.5
Show answer
Correct answer: C. 13
For 2D vectors, dot product is x1x2 + y1y2.
Q43.Value of 1 + cot²θ is:
- A.sin²θ
- B.csc²θ
- C.sec²θ
- D.1
Show answer
Correct answer: B. csc²θ
1 + cot²θ = csc²θ.
Q44.If log10(x) = 2, then x equals:
- A.100
- B.2
- C.20
- D.10
Show answer
Correct answer: A. 100
From log10(x)=p, x=10^p.
Q45.Limit of (x^2 - 4)/(x - 2) as x tends to 2 is:
- A.2
- B.7
- C.5
- D.4
Show answer
Correct answer: D. 4
Factor numerator: (x-n)(x+n), cancel and substitute x=n.
Q46.If roots of x² − 14x + 45 = 0 are α and β, value of α·β is:
- A.47
- B.43
- C.45
- D.14
Show answer
Correct answer: C. 45
For x² − Sx + P = 0, product of roots is P.
Q47.Sum of first 12 terms of AP with a=6, d=5 is:
- A.132
- B.402
- C.414
- D.390
Show answer
Correct answer: B. 402
Use Sn = n/2 * [2a + (n-1)d].
Q48.Value of 9C2 is:
- A.36
- B.37
- C.35
- D.18
Show answer
Correct answer: A. 36
Use nCr = n!/(r!(n-r)!).
Q49.If y = x^6, then dy/dx at x=2 equals:
- A.64
- B.12
- C.194
- D.192
Show answer
Correct answer: D. 192
Derivative of x^n is n*x^(n-1).
Q50.Integral from 0 to 3 of 4x dx is:
- A.12
- B.14
- C.18
- D.22
Show answer
Correct answer: C. 18
Integral of kx is (k/2)x^2 and then apply limits.
Q51.Area of circle of radius 8 is:
- A.72pi
- B.64pi
- C.16pi
- D.8pi
Show answer
Correct answer: B. 64pi
Area = pi*r^2.
Q52.If slopes are m1=1 and m2=-4, then m1*m2 is:
- A.-4
- B.-3
- C.5
- D.-6
Show answer
Correct answer: A. -4
Multiply the two slopes directly.
Q53.Determinant of matrix [[3, 4], [2, 5]] is:
- A.23
- B.14
- C.10
- D.7
Show answer
Correct answer: D. 7
For 2x2 matrix, determinant = ad - bc.
Q54.Value of 9P3 is:
- A.510
- B.498
- C.504
- D.84
Show answer
Correct answer: C. 504
nPr = n!/(n-r)!.
Q55.Two balls are drawn without replacement from a bag having 7 red and 8 blue balls. Probability that both are red is:
- A.56/210
- B.42/210
- C.7/15
- D.42/15
Show answer
Correct answer: B. 42/210
Use P(R1 and R2) = (red/total)*((red-1)/(total-1)).
Q56.Modulus of complex number 3 + 7i is:
- A.7.62
- B.10
- C.4
- D.21
Show answer
Correct answer: A. 7.62
|a+bi| = sqrt(a^2 + b^2).
Q57.Dot product of vectors (4, 3) and (4, 2) is:
- A.10
- B.24
- C.20
- D.22
Show answer
Correct answer: D. 22
For 2D vectors, dot product is x1x2 + y1y2.
Q58.Value of sin(90° − θ) is:
- A.−cosθ
- B.tanθ
- C.cosθ
- D.sinθ
Show answer
Correct answer: C. cosθ
Co-function identity: sin(90°−θ) = cosθ.
Q59.If log10(x) = 5, then x equals:
- A.10000
- B.100000
- C.5
- D.50
Show answer
Correct answer: B. 100000
From log10(x)=p, x=10^p.
Q60.Limit of (x^2 - 1)/(x - 1) as x tends to 1 is:
- A.2
- B.1
- C.4
- D.3
Show answer
Correct answer: A. 2
Factor numerator: (x-n)(x+n), cancel and substitute x=n.
Q61.For uniformly accelerated motion (u=2 m/s, a=4 m/s², t=4 s), final velocity is:
- A.14 m/s
- B.22 m/s
- C.6 m/s
- D.18 m/s
Show answer
Correct answer: D. 18 m/s
Use v = u + at.
Q62.Maximum height reached by a body projected vertically upward with speed 22 m/s (g=10 m/s^2) is:
- A.26.2 m
- B.22.2 m
- C.24.2 m
- D.22 m
Show answer
Correct answer: C. 24.2 m
Use H = u^2/(2g).
Q63.A 5 kg body has acceleration 3 m/s^2. Net force is:
- A.3 N
- B.15 N
- C.17 N
- D.13 N
Show answer
Correct answer: B. 15 N
Use F = ma.
Q64.Kinetic energy of mass 3 kg moving at 4 m/s is:
- A.24 J
- B.29 J
- C.19 J
- D.12 J
Show answer
Correct answer: A. 24 J
Use KE = 1/2 mv^2.
Q65.If 250 J work is done in 8 s, power is:
- A.35.25 W
- B.27.25 W
- C.8 W
- D.31.25 W
Show answer
Correct answer: D. 31.25 W
Power = Work/time.
Q66.If distance between two masses becomes 2 times its original value, gravitational force becomes:
- A.2 times
- B.unchanged
- C.1/4
- D.1/2
Show answer
Correct answer: C. 1/4
F ∝ 1/r². New F = F₀/2² = 1/4 of original.
Q67.For mass-spring system (m=1 kg, k=150 N/m), time period is:
- A.0.08 s
- B.0.51 s
- C.0.71 s
- D.0.31 s
Show answer
Correct answer: B. 0.51 s
Use T = 2*pi*sqrt(m/k).
Q68.A wave has frequency 40 Hz and wavelength 2 m. Speed is:
- A.80 m/s
- B.90 m/s
- C.70 m/s
- D.42 m/s
Show answer
Correct answer: A. 80 m/s
Use v = f*lambda.
Q69.A heat engine absorbs 550 J and rejects 200 J. Efficiency is:
- A.68.64%
- B.58.64%
- C.36.36%
- D.63.64%
Show answer
Correct answer: D. 63.64%
Efficiency = (Qh-Qc)/Qh.
Q70.If separation between two point charges is made 2 times its original value, electrostatic force becomes:
- A.2 times
- B.unchanged
- C.1/4
- D.1/2
Show answer
Correct answer: C. 1/4
Coulomb’s law: F ∝ 1/r². New F = F₀/2² = 1/4 of original.
Q71.Equivalent resistance of 5 ohm and 4 ohm in parallel is:
- A.3.22 ohm
- B.2.22 ohm
- C.9 ohm
- D.1 ohm
Show answer
Correct answer: B. 2.22 ohm
For parallel combination, R = R1*R2/(R1+R2).
Q72.Potential difference across 5 ohm carrying 2 A current is:
- A.10 V
- B.12 V
- C.8 V
- D.7 V
Show answer
Correct answer: A. 10 V
Ohm law: V = IR.
Q73.A charge 3 C moves perpendicular to magnetic field 5 T with speed 4 m/s. Magnetic force is:
- A.62 N
- B.58 N
- C.12 N
- D.60 N
Show answer
Correct answer: D. 60 N
Use F = qvB for perpendicular motion.
Q74.A 24-turn coil has flux change 5 Wb in 0.5 s. Induced emf magnitude is:
- A.238 V
- B.5 V
- C.240 V
- D.242 V
Show answer
Correct answer: C. 240 V
Faraday law: emf = N*(dPhi/dt).
Q75.In photoelectric effect, if frequency increases beyond threshold, KEₘₐₓ of emitted electrons:
- A.remains constant
- B.increases linearly
- C.decreases
- D.remains zero
Show answer
Correct answer: B. increases linearly
KEₘₐₓ = hν − φ; KE increases linearly with frequency.
Q76.For uniformly accelerated motion (u=3 m/s, a=3 m/s², t=4 s), final velocity is:
- A.15 m/s
- B.12 m/s
- C.18 m/s
- D.7 m/s
Show answer
Correct answer: A. 15 m/s
Use v = u + at.
Q77.Maximum height reached by a body projected vertically upward with speed 25 m/s (g=10 m/s^2) is:
- A.25 m
- B.33.25 m
- C.29.25 m
- D.31.25 m
Show answer
Correct answer: D. 31.25 m
Use H = u^2/(2g).
Q78.A 5 kg body has acceleration 4 m/s^2. Net force is:
- A.18 N
- B.4 N
- C.20 N
- D.22 N
Show answer
Correct answer: C. 20 N
Use F = ma.
Q79.Kinetic energy of mass 6 kg moving at 5 m/s is:
- A.30 J
- B.75 J
- C.80 J
- D.70 J
Show answer
Correct answer: B. 75 J
Use KE = 1/2 mv^2.
Q80.If 280 J work is done in 8 s, power is:
- A.35 W
- B.39 W
- C.31 W
- D.8 W
Show answer
Correct answer: A. 35 W
Power = Work/time.
Q81.If distance between two masses becomes 3 times its original value, gravitational force becomes:
- A.1/4
- B.1/2
- C.unchanged
- D.1/9
Show answer
Correct answer: D. 1/9
F ∝ 1/r². New F = F₀/3² = 1/9 of original.
Q82.For mass-spring system (m=2 kg, k=175 N/m), time period is:
- A.0.47 s
- B.0.11 s
- C.0.67 s
- D.0.87 s
Show answer
Correct answer: C. 0.67 s
Use T = 2*pi*sqrt(m/k).
Q83.A wave has frequency 70 Hz and wavelength 3 m. Speed is:
- A.73 m/s
- B.210 m/s
- C.220 m/s
- D.200 m/s
Show answer
Correct answer: B. 210 m/s
Use v = f*lambda.
Q84.A heat engine absorbs 500 J and rejects 220 J. Efficiency is:
- A.56%
- B.61%
- C.51%
- D.44%
Show answer
Correct answer: A. 56%
Efficiency = (Qh-Qc)/Qh.
Q85.If separation between two point charges is made 3 times its original value, electrostatic force becomes:
- A.1/4
- B.1/2
- C.unchanged
- D.1/9
Show answer
Correct answer: D. 1/9
Coulomb’s law: F ∝ 1/r². New F = F₀/3² = 1/9 of original.
Q86.Equivalent resistance of 4 ohm and 4 ohm in parallel is:
- A.0 ohm
- B.3 ohm
- C.2 ohm
- D.8 ohm
Show answer
Correct answer: C. 2 ohm
For parallel combination, R = R1*R2/(R1+R2).
Q87.Potential difference across 5 ohm carrying 5 A current is:
- A.10 V
- B.25 V
- C.27 V
- D.23 V
Show answer
Correct answer: B. 25 V
Ohm law: V = IR.
Q88.A charge 3 C moves perpendicular to magnetic field 4 T with speed 3 m/s. Magnetic force is:
- A.36 N
- B.38 N
- C.34 N
- D.10 N
Show answer
Correct answer: A. 36 N
Use F = qvB for perpendicular motion.
Q89.A 24-turn coil has flux change 4 Wb in 0.5 s. Induced emf magnitude is:
- A.194 V
- B.190 V
- C.4 V
- D.192 V
Show answer
Correct answer: D. 192 V
Faraday law: emf = N*(dPhi/dt).
Q90.In photoelectric effect, threshold frequency is:
- A.frequency of emitted electron
- B.frequency of X-rays
- C.minimum frequency to eject an electron
- D.maximum frequency of light
Show answer
Correct answer: C. minimum frequency to eject an electron
Below ν₀, no photoelectric effect occurs.
Q91.For uniformly accelerated motion (u=4 m/s, a=6 m/s², t=4 s), final velocity is:
- A.8 m/s
- B.28 m/s
- C.22 m/s
- D.34 m/s
Show answer
Correct answer: B. 28 m/s
Use v = u + at.
Q92.Maximum height reached by a body projected vertically upward with speed 28 m/s (g=10 m/s^2) is:
- A.39.2 m
- B.28 m
- C.41.2 m
- D.37.2 m
Show answer
Correct answer: A. 39.2 m
Use H = u^2/(2g).
Q93.A 5 kg body has acceleration 5 m/s^2. Net force is:
- A.27 N
- B.23 N
- C.5 N
- D.25 N
Show answer
Correct answer: D. 25 N
Use F = ma.
Q94.Kinetic energy of mass 5 kg moving at 6 m/s is:
- A.85 J
- B.30 J
- C.90 J
- D.95 J
Show answer
Correct answer: C. 90 J
Use KE = 1/2 mv^2.
Q95.If 310 J work is done in 8 s, power is:
- A.8 W
- B.38.75 W
- C.42.75 W
- D.34.75 W
Show answer
Correct answer: B. 38.75 W
Power = Work/time.
Q96.If distance between two masses becomes 4 times its original value, gravitational force becomes:
- A.1/16
- B.1/4
- C.1/2
- D.unchanged
Show answer
Correct answer: A. 1/16
F ∝ 1/r². New F = F₀/4² = 1/16 of original.
Q97.For mass-spring system (m=3 kg, k=100 N/m), time period is:
- A.1.29 s
- B.0.89 s
- C.0.17 s
- D.1.09 s
Show answer
Correct answer: D. 1.09 s
Use T = 2*pi*sqrt(m/k).
Q98.A wave has frequency 60 Hz and wavelength 4 m. Speed is:
- A.230 m/s
- B.64 m/s
- C.240 m/s
- D.250 m/s
Show answer
Correct answer: C. 240 m/s
Use v = f*lambda.
Q99.A heat engine absorbs 650 J and rejects 240 J. Efficiency is:
- A.36.92%
- B.63.08%
- C.68.08%
- D.58.08%
Show answer
Correct answer: B. 63.08%
Efficiency = (Qh-Qc)/Qh.
Q100.If separation between two point charges is made 4 times its original value, electrostatic force becomes:
- A.1/16
- B.1/4
- C.1/2
- D.unchanged
Show answer
Correct answer: A. 1/16
Coulomb’s law: F ∝ 1/r². New F = F₀/4² = 1/16 of original.
Q101.Equivalent resistance of 3 ohm and 4 ohm in parallel is:
- A.7 ohm
- B.1 ohm
- C.2.71 ohm
- D.1.71 ohm
Show answer
Correct answer: D. 1.71 ohm
For parallel combination, R = R1*R2/(R1+R2).
Q102.Potential difference across 5 ohm carrying 4 A current is:
- A.18 V
- B.9 V
- C.20 V
- D.22 V
Show answer
Correct answer: C. 20 V
Ohm law: V = IR.
Q103.A charge 3 C moves perpendicular to magnetic field 5 T with speed 6 m/s. Magnetic force is:
- A.14 N
- B.90 N
- C.92 N
- D.88 N
Show answer
Correct answer: B. 90 N
Use F = qvB for perpendicular motion.
Q104.A 24-turn coil has flux change 3 Wb in 0.5 s. Induced emf magnitude is:
- A.144 V
- B.146 V
- C.142 V
- D.3 V
Show answer
Correct answer: A. 144 V
Faraday law: emf = N*(dPhi/dt).
Q105.Work function in photoelectric effect is:
- A.kinetic energy of emitted electron
- B.energy of incident photon
- C.energy of X-rays
- D.minimum energy needed to eject an electron from metal surface
Show answer
Correct answer: D. minimum energy needed to eject an electron from metal surface
Work function φ = hν₀.
Q106.For uniformly accelerated motion (u=5 m/s, a=5 m/s², t=4 s), final velocity is:
- A.30 m/s
- B.9 m/s
- C.25 m/s
- D.20 m/s
Show answer
Correct answer: C. 25 m/s
Use v = u + at.
Q107.Maximum height reached by a body projected vertically upward with speed 31 m/s (g=10 m/s^2) is:
- A.46.05 m
- B.48.05 m
- C.31 m
- D.50.05 m
Show answer
Correct answer: B. 48.05 m
Use H = u^2/(2g).
Q108.A 5 kg body has acceleration 6 m/s^2. Net force is:
- A.30 N
- B.32 N
- C.28 N
- D.6 N
Show answer
Correct answer: A. 30 N
Use F = ma.
Q109.Kinetic energy of mass 4 kg moving at 7 m/s is:
- A.103 J
- B.93 J
- C.28 J
- D.98 J
Show answer
Correct answer: D. 98 J
Use KE = 1/2 mv^2.
Q110.If 340 J work is done in 8 s, power is:
- A.38.5 W
- B.8 W
- C.42.5 W
- D.46.5 W
Show answer
Correct answer: C. 42.5 W
Power = Work/time.
Q111.If distance between two masses becomes 5 times its original value, gravitational force becomes:
- A.unchanged
- B.1/25
- C.1/4
- D.1/2
Show answer
Correct answer: B. 1/25
F ∝ 1/r². New F = F₀/5² = 1/25 of original.
Q112.For mass-spring system (m=4 kg, k=125 N/m), time period is:
- A.1.12 s
- B.1.32 s
- C.0.92 s
- D.0.18 s
Show answer
Correct answer: A. 1.12 s
Use T = 2*pi*sqrt(m/k).
Q113.A wave has frequency 50 Hz and wavelength 5 m. Speed is:
- A.260 m/s
- B.240 m/s
- C.55 m/s
- D.250 m/s
Show answer
Correct answer: D. 250 m/s
Use v = f*lambda.
Q114.A heat engine absorbs 600 J and rejects 260 J. Efficiency is:
- A.51.67%
- B.43.33%
- C.56.67%
- D.61.67%
Show answer
Correct answer: C. 56.67%
Efficiency = (Qh-Qc)/Qh.
Q115.If separation between two point charges is made 5 times its original value, electrostatic force becomes:
- A.unchanged
- B.1/25
- C.1/4
- D.1/2
Show answer
Correct answer: B. 1/25
Coulomb’s law: F ∝ 1/r². New F = F₀/5² = 1/25 of original.
Q116.Equivalent resistance of 2 ohm and 4 ohm in parallel is:
- A.1.33 ohm
- B.6 ohm
- C.2 ohm
- D.2.33 ohm
Show answer
Correct answer: A. 1.33 ohm
For parallel combination, R = R1*R2/(R1+R2).
Q117.Potential difference across 5 ohm carrying 3 A current is:
- A.17 V
- B.13 V
- C.8 V
- D.15 V
Show answer
Correct answer: D. 15 V
Ohm law: V = IR.
Q118.A charge 3 C moves perpendicular to magnetic field 4 T with speed 5 m/s. Magnetic force is:
- A.58 N
- B.12 N
- C.60 N
- D.62 N
Show answer
Correct answer: C. 60 N
Use F = qvB for perpendicular motion.
Q119.A 24-turn coil has flux change 6 Wb in 0.5 s. Induced emf magnitude is:
- A.6 V
- B.288 V
- C.290 V
- D.286 V
Show answer
Correct answer: B. 288 V
Faraday law: emf = N*(dPhi/dt).
Q120.Stopping potential in photoelectric experiment is voltage needed to:
- A.stop the fastest emitted electrons
- B.accelerate electrons
- C.increase photon frequency
- D.reflect photons
Show answer
Correct answer: A. stop the fastest emitted electrons
eVₛ = KEₘₐₓ; stopping potential arrests maximum-energy electrons.
Q121.Number of moles in 33 g of CO2 is:
- A.1.25
- B.0.5
- C.1.75
- D.0.75
Show answer
Correct answer: D. 0.75
Moles = mass/molar mass.
Q122.At constant temperature, pressure of a gas is inversely proportional to volume. This is:
- A.Gay-Lussac’s law
- B.Avogadro’s law
- C.Boyle’s law
- D.Charles’ law
Show answer
Correct answer: C. Boyle’s law
Boyle’s law: P ∝ 1/V at constant T.
Q123.A reaction that absorbs heat from surroundings is:
- A.adiabatic
- B.endothermic
- C.exothermic
- D.isothermal
Show answer
Correct answer: B. endothermic
Endothermic reaction absorbs heat (ΔH > 0).
Q124.For a reaction with Δn = 1, if Kp = 4 and RT = 2, then Kc is:
- A.2
- B.8
- C.6
- D.3.5
Show answer
Correct answer: A. 2
Kp = Kc×(RT)ᴵⁿ; here Kc = Kp/RT = 4/2 = 2.
Q125.Anode in a galvanic cell is the electrode where:
- A.reduction occurs
- B.ions are reduced only
- C.electrons are consumed
- D.oxidation occurs
Show answer
Correct answer: D. oxidation occurs
Oxidation always occurs at anode.
Q126.For first-order reaction, unit of rate constant is:
- A.L mol⁻¹ s⁻¹
- B.mol⁻¹ s⁻¹
- C.s⁻¹
- D.mol L⁻¹ s⁻¹
Show answer
Correct answer: C. s⁻¹
For first-order, unit of k is time⁻¹ (s⁻¹).
Q127.Maximum number of electrons in p-subshell is:
- A.14
- B.6
- C.2
- D.10
Show answer
Correct answer: B. 6
p has 3 orbitals × 2 electrons = 6.
Q128.Element with highest electronegativity is:
- A.Fluorine
- B.Oxygen
- C.Chlorine
- D.Nitrogen
Show answer
Correct answer: A. Fluorine
Fluorine has highest electronegativity (Pauling: 3.98).
Q129.Molecular shape of NH₃ is:
- A.tetrahedral
- B.trigonal planar
- C.linear
- D.trigonal pyramidal
Show answer
Correct answer: D. trigonal pyramidal
NH₃: 3 bond pairs + 1 lone pair → trigonal pyramidal.
Q130.Coordination number of Fe in [Fe(CN)₆]⁴⁻ is:
- A.2
- B.8
- C.6
- D.4
Show answer
Correct answer: C. 6
6 cyanide ligands around Fe → CN = 6.
Q131.Main product of addition of H₂ to ethene is:
- A.methane
- B.ethane
- C.ethyne
- D.ethanol
Show answer
Correct answer: B. ethane
Hydrogenation: CH₂=CH₂ + H₂ → CH₃CH₃ (ethane).
Q132.Hydrolysis of CH₃Cl in aqueous KOH gives:
- A.methanol
- B.methane
- C.chloromethane
- D.formaldehyde
Show answer
Correct answer: A. methanol
CH₃Cl + KOH(aq) → CH₃OH + KCl.
Q133.IUPAC name of CH₃CH₂CH₂CH₂OH is:
- A.butan-2-ol
- B.propan-1-ol
- C.pentan-1-ol
- D.butan-1-ol
Show answer
Correct answer: D. butan-1-ol
CH₃(CH₂)₃OH: 4-carbon chain, OH on C1 → butan-1-ol.
Q134.Tollens’ reagent gives silver mirror test with:
- A.alkanes
- B.ethers
- C.aldehydes
- D.ketones
Show answer
Correct answer: C. aldehydes
Aldehydes reduce [Ag(NH₃)₂]⁺ → silver mirror.
Q135.Monomer unit of polyethene is:
- A.benzene
- B.ethene
- C.ethane
- D.ethyne
Show answer
Correct answer: B. ethene
Polyethene forms by polymerisation of ethene (CH₂=CH₂).
Q136.Number of moles in 22 g of CO2 is:
- A.0.5
- B.1
- C.0.25
- D.1.5
Show answer
Correct answer: A. 0.5
Moles = mass/molar mass.
Q137.At constant pressure, volume of a gas is directly proportional to temperature. This is:
- A.Boyle’s law
- B.Gay-Lussac’s law
- C.Dalton’s law
- D.Charles’ law
Show answer
Correct answer: D. Charles’ law
Charles’ law: V ∝ T at constant P.
Q138.A reaction that releases heat to surroundings is:
- A.isothermal
- B.reversible
- C.exothermic
- D.endothermic
Show answer
Correct answer: C. exothermic
Exothermic reaction releases heat (ΔH < 0).
Q139.For a reaction with Δn = 1, if Kp = 5 and RT = 2, then Kc is:
- A.4
- B.2.5
- C.10
- D.7
Show answer
Correct answer: B. 2.5
Kp = Kc×(RT)ᴵⁿ; here Kc = Kp/RT = 5/2 = 2.5.
Q140.Cathode in an electrolytic cell is where:
- A.reduction occurs
- B.oxidation occurs
- C.cations are repelled
- D.electrons are removed
Show answer
Correct answer: A. reduction occurs
Reduction occurs at cathode in both galvanic and electrolytic cells.
Q141.For second-order reaction, unit of rate constant is:
- A.s⁻¹
- B.mol L⁻¹ s⁻¹
- C.mol⁻² L² s⁻¹
- D.L mol⁻¹ s⁻¹
Show answer
Correct answer: D. L mol⁻¹ s⁻¹
For second-order, k unit is L mol⁻¹ s⁻¹.
Q142.Maximum number of electrons in d-subshell is:
- A.6
- B.14
- C.10
- D.2
Show answer
Correct answer: C. 10
d has 5 orbitals × 2 electrons = 10.
Q143.Atomic radius generally increases going:
- A.left to right across period
- B.down a group
- C.across a period
- D.from metals to non-metals
Show answer
Correct answer: B. down a group
Atomic radius increases down a group due to additional shells.
Q144.Molecular shape of H₂O is:
- A.bent (V-shaped)
- B.linear
- C.trigonal planar
- D.tetrahedral
Show answer
Correct answer: A. bent (V-shaped)
H₂O: 2 bond pairs + 2 lone pairs → bent.
Q145.Coordination number of Cu in [Cu(NH₃)₄]²⁺ is:
- A.2
- B.6
- C.8
- D.4
Show answer
Correct answer: D. 4
4 ammonia ligands around Cu → CN = 4.
Q146.Main product of addition of HBr to propene (Markovnikov) is:
- A.1-bromopropene
- B.propanol
- C.2-bromopropane
- D.1-bromopropane
Show answer
Correct answer: C. 2-bromopropane
Markovnikov: H adds to C with more H’s → 2-bromopropane.
Q147.SN2 reaction is favoured by:
- A.bulky substrates
- B.primary haloalkanes in polar aprotic solvent
- C.tertiary haloalkanes
- D.polar protic solvents
Show answer
Correct answer: B. primary haloalkanes in polar aprotic solvent
SN2 needs easy backside attack → primary haloalkanes are best.
Q148.IUPAC name of (CH₃)₃COH is:
- A.2-methylpropan-2-ol
- B.propan-2-ol
- C.butan-2-ol
- D.propan-1-ol
Show answer
Correct answer: A. 2-methylpropan-2-ol
(CH₃)₃COH: 4 carbons, OH on C2, methyl on C2 → 2-methylpropan-2-ol.
Q149.Iodoform test is positive for:
- A.all ketones
- B.carboxylic acids
- C.esters
- D.methyl ketones and acetaldehyde
Show answer
Correct answer: D. methyl ketones and acetaldehyde
Iodoform (CHI₃) forms with compounds containing CH₃CO– group (methyl ketones and acetaldehyde).
Q150.Monomer unit of polypropylene is:
- A.propyne
- B.ethene
- C.propene
- D.propane
Show answer
Correct answer: C. propene
Polypropylene forms from propene (CH₂=CHCH₃).
Q151.Number of moles in 55 g of CO2 is:
- A.2.25
- B.1.25
- C.1.75
- D.1
Show answer
Correct answer: B. 1.25
Moles = mass/molar mass.
Q152.At constant volume, pressure of a gas is directly proportional to temperature. This is:
- A.Gay-Lussac’s law
- B.Boyle’s law
- C.Charles’ law
- D.Avogadro’s law
Show answer
Correct answer: A. Gay-Lussac’s law
Gay-Lussac’s law: P ∝ T at constant V.
Q153.Hess’s law states that enthalpy change is:
- A.path-dependent
- B.always positive
- C.always zero
- D.independent of path (state function)
Show answer
Correct answer: D. independent of path (state function)
Hess’s law: ΔH is a state function.
Q154.For a reaction with Δn = 1, if Kp = 6 and RT = 2, then Kc is:
- A.8
- B.4.5
- C.3
- D.12
Show answer
Correct answer: C. 3
Kp = Kc×(RT)ᴵⁿ; here Kc = Kp/RT = 6/2 = 3.
Q155.EMF of a galvanic cell is given by:
- A.E°cell = E°anode / E°cathode
- B.E°cell = E°cathode − E°anode
- C.E°cell = E°anode − E°cathode
- D.E°cell = E°cathode + E°anode
Show answer
Correct answer: B. E°cell = E°cathode − E°anode
E°cell = E°(reduction at cathode) − E°(reduction at anode).
Q156.Rate of reaction generally increases with temperature because:
- A.more molecules have energy ≥ activation energy
- B.activation energy decreases to zero
- C.all molecules speed up equally
- D.collision frequency only increases
Show answer
Correct answer: A. more molecules have energy ≥ activation energy
Arrhenius: k = Ae⁻(Ea/RT); higher T → more molecules exceed Ea.
Q157.Maximum number of electrons in f-subshell is:
- A.2
- B.6
- C.10
- D.14
Show answer
Correct answer: D. 14
f has 7 orbitals × 2 electrons = 14.
Q158.Ionisation energy generally decreases going:
- A.from non-metals to metals
- B.from right to left in a period
- C.down a group
- D.across a period
Show answer
Correct answer: C. down a group
Ionisation energy decreases down a group; outer electrons are farther.
Q159.Molecular shape of CO₂ is:
- A.tetrahedral
- B.linear
- C.bent
- D.trigonal planar
Show answer
Correct answer: B. linear
CO₂: 2 double bonds, no lone pairs → linear.
Q160.IUPAC name for [Co(NH₃)₆]³⁺ is:
- A.hexaamminecobalt(III)
- B.cobalt hexamine
- C.cobaltamine
- D.hexacobaltamine
Show answer
Correct answer: A. hexaamminecobalt(III)
6 NH₃ ligands = hexaammine; Co is +3 → cobalt(III).
Q161.Product of combustion of ethane (complete) is:
- A.CO and H₂O
- B.C and H₂
- C.CO₂ and H₂
- D.CO₂ and H₂O
Show answer
Correct answer: D. CO₂ and H₂O
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O.
Q162.Product of reaction of 2-bromopropane with KOH (alcoholic) is:
- A.propane
- B.propanoic acid
- C.propene (elimination)
- D.propanol (substitution)
Show answer
Correct answer: C. propene (elimination)
Alcoholic KOH causes elimination: 2-BrC₃H₇ → CH₃CH=CH₂.
Q163.IUPAC name of (CH₃)₂CHOH is:
- A.ethanol
- B.propan-2-ol
- C.propan-1-ol
- D.2-propanol (common only)
Show answer
Correct answer: B. propan-2-ol
(CH₃)₂CHOH: 3-carbon chain, OH on C2 → propan-2-ol.
Q164.Benedict’s test is positive for:
- A.reducing sugars (glucose, maltose)
- B.non-reducing sugars (sucrose)
- C.all carbohydrates
- D.lipids
Show answer
Correct answer: A. reducing sugars (glucose, maltose)
Benedict’s test detects reducing sugars.
Q165.Type of polymerisation used to make nylon-6,6 is:
- A.addition polymerisation
- B.chain-growth polymerisation
- C.ring-opening only
- D.condensation polymerisation
Show answer
Correct answer: D. condensation polymerisation
Nylon-6,6 forms by condensation of hexamethylenediamine and adipic acid.
Q166.Number of moles in 44 g of CO2 is:
- A.0.75
- B.2
- C.1
- D.1.5
Show answer
Correct answer: C. 1
Moles = mass/molar mass.
Q167.Equal volumes of all gases at same T and P contain equal number of molecules. This is:
- A.Dalton’s law
- B.Avogadro’s law
- C.Boyle’s law
- D.Charles’ law
Show answer
Correct answer: B. Avogadro’s law
Avogadro’s law: V ∝ n at same T and P.
Q168.Standard enthalpy of formation is defined for:
- A.formation of 1 mol from elements in standard states
- B.decomposition of 1 mol compound
- C.combustion of 1 mol fuel
- D.neutralisation of 1 mol acid
Show answer
Correct answer: A. formation of 1 mol from elements in standard states
ΔƒH° = enthalpy for forming 1 mol from elements.
Q169.For a reaction with Δn = 1, if Kp = 7 and RT = 2, then Kc is:
- A.14
- B.9
- C.5
- D.3.5
Show answer
Correct answer: D. 3.5
Kp = Kc×(RT)ᴵⁿ; here Kc = Kp/RT = 7/2 = 3.5.
Q170.In electrolysis of CuSO₄, metal deposited at cathode is:
- A.oxygen
- B.hydrogen
- C.copper
- D.sulfur
Show answer
Correct answer: C. copper
Cu²⁺ is reduced at cathode: Cu²⁺ + 2e⁻ → Cu.
Q171.Half-life of first-order reaction is:
- A.equal to rate constant
- B.independent of initial concentration
- C.directly proportional to concentration
- D.inversely proportional to concentration
Show answer
Correct answer: B. independent of initial concentration
t½ = ln2/k for first-order; does not depend on [A]₀.
Q172.Maximum number of electrons in s-subshell is:
- A.2
- B.6
- C.10
- D.14
Show answer
Correct answer: A. 2
s has 1 orbital × 2 electrons = 2.
Q173.Electron affinity is generally most negative for:
- A.noble gases
- B.alkali metals
- C.alkaline earth metals
- D.halogens (especially Cl)
Show answer
Correct answer: D. halogens (especially Cl)
Cl has highest electron affinity among all elements.
Q174.Molecular shape of BF₃ is:
- A.tetrahedral
- B.linear
- C.trigonal planar
- D.pyramidal
Show answer
Correct answer: C. trigonal planar
BF₃: 3 bond pairs, no lone pairs → trigonal planar.
Q175.A ligand that donates two pairs of electrons is called:
- A.ambidentate
- B.bidentate
- C.monodentate
- D.tridentate
Show answer
Correct answer: B. bidentate
Bidentate ligands donate 2 electron pairs (e.g. en, oxalate).
Q176.Benzene undergoes electrophilic substitution rather than addition because:
- A.it is stabilised by aromaticity
- B.it has no double bonds
- C.it is a saturated compound
- D.it reacts only with metals
Show answer
Correct answer: A. it is stabilised by aromaticity
Aromatic stability is maintained by substitution, not addition.
Q177.In SN1 reaction, intermediate formed is:
- A.carbanion
- B.free radical
- C.transition state only
- D.carbocation
Show answer
Correct answer: D. carbocation
SN1: ionisation → carbocation intermediate, then nucleophile attacks.
Q178.IUPAC name of CH₃CH₂CH₂OH is:
- A.ethanol
- B.propanoic acid
- C.propan-1-ol
- D.propan-2-ol
Show answer
Correct answer: C. propan-1-ol
CH₃CH₂CH₂OH: 3-carbon chain, OH on C1 → propan-1-ol.
Q179.Schiff’s reagent is used to distinguish:
- A.acids from bases
- B.aldehydes from ketones
- C.alcohols from esters
- D.alkanes from alkenes
Show answer
Correct answer: B. aldehydes from ketones
Schiff’s reagent turns pink/violet with aldehydes, not ketones.
Q180.Natural polymer that makes up plant cell walls is:
- A.cellulose
- B.starch
- C.glycogen
- D.chitin
Show answer
Correct answer: A. cellulose
Cellulose: β-glucose polymer that forms plant cell walls.