COMEDK Practice Set 5
Original COMEDK-style full-length set with 180 questions: 60 Mathematics, 60 Physics, and 60 Chemistry.
Exam Pattern & Rules
Negative Marking: No negative marking
Note: 60 MCQs each in Physics, Chemistry, and Mathematics.
Practice Set Details
COMEDK Practice Set 5: all 180 questions with answers
Try each question first, then open “Show answer” to check the correct option and explanation.
Q1.Solve for x: 8x + 7 = 31.
- A.4
- B.2
- C.5
- D.3
Show answer
Correct answer: D. 3
Subtract 7 from both sides: 8x = 24. Divide by 8: x = 3.
Q2.One root of x² − 16x + 63 = 0 is 7. The other root is:
- A.8
- B.16
- C.9
- D.10
Show answer
Correct answer: C. 9
Product of roots = 63. Other root = 63 ÷ 7 = 9.
Q3.The 8th term of an AP with first term 2 and common difference 8 is:
- A.61
- B.58
- C.50
- D.66
Show answer
Correct answer: B. 58
aₙ = a + (n−1)d = 2 + 7×8 = 58.
Q4.Slope of the line through (3, 8) and (6, 26) is:
- A.6
- B.7
- C.5
- D.8
Show answer
Correct answer: A. 6
Slope = (26−8) ÷ (6−3) = 18 ÷ 3 = 6.
Q5.Value of cos 270° is:
- A.1
- B.−1
- C.1/2
- D.0
Show answer
Correct answer: D. 0
cos 270° = 0.
Q6.A bag contains 7 red and 7 blue balls. Probability of drawing a red ball is:
- A.7/13
- B.8/15
- C.7/14
- D.7/15
Show answer
Correct answer: C. 7/14
P(red) = 7/14.
Q7.Determinant of matrix [[8, 1], [2, 7]] is:
- A.22
- B.54
- C.59
- D.51
Show answer
Correct answer: B. 54
det = ad − bc = 8×7 − 1×2 = 54.
Q8.Evaluate: log₂ₐₑₒₓ2(2^8) [log base 2].
- A.8
- B.9
- C.7
- D.16
Show answer
Correct answer: A. 8
logₐ(a^n) = n, so log_2(2^8) = 8.
Q9.Find 10P4.
- A.1260
- B.5048
- C.5032
- D.5040
Show answer
Correct answer: D. 5040
10P4 = 10!/(10−4)! = 10×9×8×7 = 5040.
Q10.Find 9C2.
- A.39
- B.33
- C.36
- D.18
Show answer
Correct answer: C. 36
nC2 = n(n−1)/2 = 9×8/2 = 36.
Q11.Simple interest on Rs 4500 at 6% p.a. for 2 years is:
- A.Rs 1080
- B.Rs 540
- C.Rs 660
- D.Rs 480
Show answer
Correct answer: B. Rs 540
SI = P×R×T/100 = 4500×6×2/100 = Rs 540.
Q12.Area of a triangle with base 6 cm and height 6 cm is:
- A.18 cm²
- B.36 cm²
- C.24 cm²
- D.12 cm²
Show answer
Correct answer: A. 18 cm²
Area = (1/2) × base × height = (1/2) × 6 × 6 = 18 cm².
Q13.Solve for x: 2x + 8 = 16.
- A.5
- B.3
- C.6
- D.4
Show answer
Correct answer: D. 4
Subtract 8 from both sides: 2x = 8. Divide by 2: x = 4.
Q14.One root of x² − 19x + 88 = 0 is 8. The other root is:
- A.10
- B.19
- C.11
- D.12
Show answer
Correct answer: C. 11
Product of roots = 88. Other root = 88 ÷ 8 = 11.
Q15.The 9th term of an AP with first term 3 and common difference 2 is:
- A.23
- B.19
- C.17
- D.21
Show answer
Correct answer: B. 19
aₙ = a + (n−1)d = 3 + 8×2 = 19.
Q16.Slope of the line through (4, 2) and (7, 23) is:
- A.7
- B.8
- C.6
- D.9
Show answer
Correct answer: A. 7
Slope = (23−2) ÷ (7−4) = 21 ÷ 3 = 7.
Q17.Value of tan 0° is:
- A.1
- B.undefined
- C.1/2
- D.0
Show answer
Correct answer: D. 0
tan 0° = 0.
Q18.A bag contains 8 red and 8 blue balls. Probability of drawing a red ball is:
- A.8/15
- B.9/17
- C.8/16
- D.8/17
Show answer
Correct answer: C. 8/16
P(red) = 8/16.
Q19.Determinant of matrix [[2, 2], [3, 8]] is:
- A.18
- B.10
- C.15
- D.7
Show answer
Correct answer: B. 10
det = ad − bc = 2×8 − 2×3 = 10.
Q20.Evaluate: log₂ₐₑₒₓ3(3^2) [log base 3].
- A.2
- B.3
- C.1
- D.6
Show answer
Correct answer: A. 2
logₐ(a^n) = n, so log_3(3^2) = 2.
Q21.Find 11P2.
- A.55
- B.114
- C.106
- D.110
Show answer
Correct answer: D. 110
11P2 = 11!/(11−2)! = 11×10 = 110.
Q22.Find 10C2.
- A.48
- B.42
- C.45
- D.20
Show answer
Correct answer: C. 45
nC2 = n(n−1)/2 = 10×9/2 = 45.
Q23.Simple interest on Rs 4700 at 7% p.a. for 3 years is:
- A.Rs 1974
- B.Rs 987
- C.Rs 1197
- D.Rs 882
Show answer
Correct answer: B. Rs 987
SI = P×R×T/100 = 4700×7×3/100 = Rs 987.
Q24.Area of a triangle with base 7 cm and height 7 cm is:
- A.24.5 cm²
- B.49 cm²
- C.30.5 cm²
- D.18.5 cm²
Show answer
Correct answer: A. 24.5 cm²
Area = (1/2) × base × height = (1/2) × 7 × 7 = 24.5 cm².
Q25.Solve for x: 3x + 9 = 24.
- A.6
- B.4
- C.7
- D.5
Show answer
Correct answer: D. 5
Subtract 9 from both sides: 3x = 15. Divide by 3: x = 5.
Q26.One root of x² − 22x + 117 = 0 is 9. The other root is:
- A.12
- B.22
- C.13
- D.14
Show answer
Correct answer: C. 13
Product of roots = 117. Other root = 117 ÷ 9 = 13.
Q27.The 10th term of an AP with first term 4 and common difference 3 is:
- A.36
- B.31
- C.28
- D.34
Show answer
Correct answer: B. 31
aₙ = a + (n−1)d = 4 + 9×3 = 31.
Q28.Slope of the line through (5, 3) and (8, 27) is:
- A.8
- B.9
- C.7
- D.10
Show answer
Correct answer: A. 8
Slope = (27−3) ÷ (8−5) = 24 ÷ 3 = 8.
Q29.Value of sin(−30°) is:
- A.1/2
- B.√3/2
- C.−1
- D.−1/2
Show answer
Correct answer: D. −1/2
sin(−θ)=−sinθ, so −1/2.
Q30.A bag contains 9 red and 9 blue balls. Probability of drawing a red ball is:
- A.9/17
- B.10/19
- C.9/18
- D.9/19
Show answer
Correct answer: C. 9/18
P(red) = 9/18.
Q31.Determinant of matrix [[3, 3], [4, 9]] is:
- A.21
- B.15
- C.20
- D.12
Show answer
Correct answer: B. 15
det = ad − bc = 3×9 − 3×4 = 15.
Q32.Evaluate: log₂ₐₑₒₓ5(5^3) [log base 5].
- A.3
- B.4
- C.2
- D.15
Show answer
Correct answer: A. 3
logₐ(a^n) = n, so log_5(5^3) = 3.
Q33.Find 12P3.
- A.440
- B.1326
- C.1314
- D.1320
Show answer
Correct answer: D. 1320
12P3 = 12!/(12−3)! = 12×11×10 = 1320.
Q34.Find 11C2.
- A.58
- B.52
- C.55
- D.22
Show answer
Correct answer: C. 55
nC2 = n(n−1)/2 = 11×10/2 = 55.
Q35.Simple interest on Rs 4900 at 8% p.a. for 4 years is:
- A.Rs 3136
- B.Rs 1568
- C.Rs 1888
- D.Rs 1408
Show answer
Correct answer: B. Rs 1568
SI = P×R×T/100 = 4900×8×4/100 = Rs 1568.
Q36.Area of a triangle with base 8 cm and height 8 cm is:
- A.32 cm²
- B.64 cm²
- C.38 cm²
- D.26 cm²
Show answer
Correct answer: A. 32 cm²
Area = (1/2) × base × height = (1/2) × 8 × 8 = 32 cm².
Q37.Solve for x: 4x + 10 = 34.
- A.7
- B.5
- C.8
- D.6
Show answer
Correct answer: D. 6
Subtract 10 from both sides: 4x = 24. Divide by 4: x = 6.
Q38.One root of x² − 25x + 150 = 0 is 10. The other root is:
- A.14
- B.25
- C.15
- D.16
Show answer
Correct answer: C. 15
Product of roots = 150. Other root = 150 ÷ 10 = 15.
Q39.The 11th term of an AP with first term 5 and common difference 4 is:
- A.51
- B.45
- C.41
- D.49
Show answer
Correct answer: B. 45
aₙ = a + (n−1)d = 5 + 10×4 = 45.
Q40.Slope of the line through (6, 4) and (9, 31) is:
- A.9
- B.10
- C.8
- D.11
Show answer
Correct answer: A. 9
Slope = (31−4) ÷ (9−6) = 27 ÷ 3 = 9.
Q41.Value of cos(−60°) is:
- A.−1/2
- B.√3/2
- C.1
- D.1/2
Show answer
Correct answer: D. 1/2
cos(−θ)=cosθ, so 1/2.
Q42.A bag contains 10 red and 10 blue balls. Probability of drawing a red ball is:
- A.10/19
- B.11/21
- C.10/20
- D.10/21
Show answer
Correct answer: C. 10/20
P(red) = 10/20.
Q43.Determinant of matrix [[4, 4], [5, 10]] is:
- A.24
- B.20
- C.25
- D.17
Show answer
Correct answer: B. 20
det = ad − bc = 4×10 − 4×5 = 20.
Q44.Evaluate: log₂ₐₑₒₓ10(10^4) [log base 10].
- A.4
- B.5
- C.3
- D.40
Show answer
Correct answer: A. 4
logₐ(a^n) = n, so log_10(10^4) = 4.
Q45.Find 13P4.
- A.4290
- B.17168
- C.17152
- D.17160
Show answer
Correct answer: D. 17160
13P4 = 13!/(13−4)! = 13×12×11×10 = 17160.
Q46.Find 12C2.
- A.69
- B.63
- C.66
- D.24
Show answer
Correct answer: C. 66
nC2 = n(n−1)/2 = 12×11/2 = 66.
Q47.Simple interest on Rs 5100 at 9% p.a. for 5 years is:
- A.Rs 4590
- B.Rs 2295
- C.Rs 2745
- D.Rs 2070
Show answer
Correct answer: B. Rs 2295
SI = P×R×T/100 = 5100×9×5/100 = Rs 2295.
Q48.Area of a triangle with base 9 cm and height 9 cm is:
- A.40.5 cm²
- B.81 cm²
- C.46.5 cm²
- D.34.5 cm²
Show answer
Correct answer: A. 40.5 cm²
Area = (1/2) × base × height = (1/2) × 9 × 9 = 40.5 cm².
Q49.Solve for x: 5x + 11 = 46.
- A.8
- B.6
- C.9
- D.7
Show answer
Correct answer: D. 7
Subtract 11 from both sides: 5x = 35. Divide by 5: x = 7.
Q50.One root of x² − 12x + 27 = 0 is 3. The other root is:
- A.8
- B.12
- C.9
- D.10
Show answer
Correct answer: C. 9
Product of roots = 27. Other root = 27 ÷ 3 = 9.
Q51.The 12th term of an AP with first term 6 and common difference 5 is:
- A.68
- B.61
- C.56
- D.66
Show answer
Correct answer: B. 61
aₙ = a + (n−1)d = 6 + 11×5 = 61.
Q52.Slope of the line through (1, 5) and (4, 11) is:
- A.2
- B.3
- C.1
- D.4
Show answer
Correct answer: A. 2
Slope = (11−5) ÷ (4−1) = 6 ÷ 3 = 2.
Q53.Value of cot 45° is:
- A.0
- B.√3
- C.1/√3
- D.1
Show answer
Correct answer: D. 1
cot 45° = cos45°/sin45° = 1.
Q54.A bag contains 3 red and 11 blue balls. Probability of drawing a red ball is:
- A.3/13
- B.12/15
- C.3/14
- D.11/15
Show answer
Correct answer: C. 3/14
P(red) = 3/14.
Q55.Determinant of matrix [[5, 5], [2, 3]] is:
- A.15
- B.5
- C.10
- D.2
Show answer
Correct answer: B. 5
det = ad − bc = 5×3 − 5×2 = 5.
Q56.Evaluate: log₂ₐₑₒₓ2(2^5) [log base 2].
- A.5
- B.6
- C.4
- D.10
Show answer
Correct answer: A. 5
logₐ(a^n) = n, so log_2(2^5) = 5.
Q57.Find 6P2.
- A.15
- B.34
- C.26
- D.30
Show answer
Correct answer: D. 30
6P2 = 6!/(6−2)! = 6×5 = 30.
Q58.Find 13C2.
- A.81
- B.75
- C.78
- D.26
Show answer
Correct answer: C. 78
nC2 = n(n−1)/2 = 13×12/2 = 78.
Q59.Simple interest on Rs 5300 at 10% p.a. for 2 years is:
- A.Rs 2120
- B.Rs 1060
- C.Rs 1260
- D.Rs 960
Show answer
Correct answer: B. Rs 1060
SI = P×R×T/100 = 5300×10×2/100 = Rs 1060.
Q60.Area of a triangle with base 10 cm and height 10 cm is:
- A.50 cm²
- B.100 cm²
- C.56 cm²
- D.44 cm²
Show answer
Correct answer: A. 50 cm²
Area = (1/2) × base × height = (1/2) × 10 × 10 = 50 cm².
Q61.A body starts with velocity 6 m/s and has acceleration 8 m/s². Its velocity after 3 s is:
- A.22 m/s
- B.38 m/s
- C.9 m/s
- D.30 m/s
Show answer
Correct answer: D. 30 m/s
v = u + at = 6 + 8×3 = 30 m/s.
Q62.For u = 3 m/s, a = 2 m/s², t = 4 s, displacement is:
- A.36 m
- B.26 m
- C.28 m
- D.12 m
Show answer
Correct answer: C. 28 m
s = ut + ½At² = 3×4 + 0.5×2×4² = 28 m.
Q63.Net force needed to give 6 kg mass an acceleration of 9 m/s² is:
- A.15 N
- B.54 N
- C.63 N
- D.45 N
Show answer
Correct answer: B. 54 N
F = ma = 6×9 = 54 N.
Q64.Work done when force 50 N moves a body 7 m in its direction is:
- A.350 J
- B.400 J
- C.300 J
- D.57 J
Show answer
Correct answer: A. 350 J
W = F×d = 50×7 = 350 J.
Q65.A body does 1100 J of work in 7 s. Its power is:
- A.314.29 W
- B.164.14 W
- C.152.14 W
- D.157.14 W
Show answer
Correct answer: D. 157.14 W
P = W/t = 1100/7 = 157.14 W.
Q66.A body of mass 7 kg moves at 6 m/s. Its momentum is:
- A.36 kg·m/s
- B.13 kg·m/s
- C.42 kg·m/s
- D.49 kg·m/s
Show answer
Correct answer: C. 42 kg·m/s
p = mv = 7×6 = 42 kg·m/s.
Q67.Kinetic energy of 8 kg body moving at 8 m/s is:
- A.248 J
- B.256 J
- C.64 J
- D.320 J
Show answer
Correct answer: B. 256 J
KE = ½mv² = 0.5×8×8² = 256 J.
Q68.Voltage across a 5 Ω resistor carrying 6 A current is:
- A.30 V
- B.35 V
- C.23 V
- D.13 V
Show answer
Correct answer: A. 30 V
V = IR = 6×5 = 30 V.
Q69.Two resistors 8 Ω and 8 Ω connected in series. Total resistance is:
- A.64 Ω
- B.0 Ω
- C.18 Ω
- D.16 Ω
Show answer
Correct answer: D. 16 Ω
Series: R = R₁ + R₂ = 8 + 8 = 16 Ω.
Q70.Power of a lens with focal length 60 cm is:
- A.2.67 D
- B.0.6 D
- C.1.67 D
- D.60 D
Show answer
Correct answer: C. 1.67 D
P = 1/f = 1/0.6 m = 1.67 D.
Q71.Wave speed for frequency 50 Hz and wavelength 8 m is:
- A.58 m/s
- B.400 m/s
- C.450 m/s
- D.320 m/s
Show answer
Correct answer: B. 400 m/s
v = fλ = 50×8 = 400 m/s.
Q72.Gravitational force doubles when one mass doubles:
- A.doubles
- B.halves
- C.quadruples
- D.unchanged
Show answer
Correct answer: A. doubles
F ∝ m₁×m₂; doubling one mass doubles F.
Q73.A body starts with velocity 7 m/s and has acceleration 2 m/s². Its velocity after 4 s is:
- A.13 m/s
- B.17 m/s
- C.11 m/s
- D.15 m/s
Show answer
Correct answer: D. 15 m/s
v = u + at = 7 + 2×4 = 15 m/s.
Q74.For u = 4 m/s, a = 3 m/s², t = 5 s, displacement is:
- A.72.5 m
- B.54.5 m
- C.57.5 m
- D.20 m
Show answer
Correct answer: C. 57.5 m
s = ut + ½At² = 4×5 + 0.5×3×5² = 57.5 m.
Q75.Net force needed to give 7 kg mass an acceleration of 3 m/s² is:
- A.10 N
- B.21 N
- C.24 N
- D.18 N
Show answer
Correct answer: B. 21 N
F = ma = 7×3 = 21 N.
Q76.Work done when force 55 N moves a body 8 m in its direction is:
- A.440 J
- B.495 J
- C.385 J
- D.63 J
Show answer
Correct answer: A. 440 J
W = F×d = 55×8 = 440 J.
Q77.A body does 1150 J of work in 8 s. Its power is:
- A.287.5 W
- B.151.75 W
- C.138.75 W
- D.143.75 W
Show answer
Correct answer: D. 143.75 W
P = W/t = 1150/8 = 143.75 W.
Q78.A body of mass 8 kg moves at 7 m/s. Its momentum is:
- A.49 kg·m/s
- B.15 kg·m/s
- C.56 kg·m/s
- D.64 kg·m/s
Show answer
Correct answer: C. 56 kg·m/s
p = mv = 8×7 = 56 kg·m/s.
Q79.Kinetic energy of 2 kg body moving at 9 m/s is:
- A.79 J
- B.81 J
- C.18 J
- D.99 J
Show answer
Correct answer: B. 81 J
KE = ½mv² = 0.5×2×9² = 81 J.
Q80.Voltage across a 6 Ω resistor carrying 7 A current is:
- A.42 V
- B.48 V
- C.34 V
- D.15 V
Show answer
Correct answer: A. 42 V
V = IR = 7×6 = 42 V.
Q81.Two resistors 9 Ω and 9 Ω connected in series. Total resistance is:
- A.81 Ω
- B.0 Ω
- C.20 Ω
- D.18 Ω
Show answer
Correct answer: D. 18 Ω
Series: R = R₁ + R₂ = 9 + 9 = 18 Ω.
Q82.Power of a lens with focal length 70 cm is:
- A.2.43 D
- B.0.7 D
- C.1.43 D
- D.70 D
Show answer
Correct answer: C. 1.43 D
P = 1/f = 1/0.7 m = 1.43 D.
Q83.Wave speed for frequency 70 Hz and wavelength 2 m is:
- A.72 m/s
- B.140 m/s
- C.210 m/s
- D.120 m/s
Show answer
Correct answer: B. 140 m/s
v = fλ = 70×2 = 140 m/s.
Q84.Gravitational force when separation is tripled becomes:
- A.1/9 of original
- B.1/3 of original
- C.3 times
- D.9 times
Show answer
Correct answer: A. 1/9 of original
F ∝ 1/r²; 3× distance → F/9.
Q85.A body starts with velocity 8 m/s and has acceleration 3 m/s². Its velocity after 5 s is:
- A.20 m/s
- B.26 m/s
- C.13 m/s
- D.23 m/s
Show answer
Correct answer: D. 23 m/s
v = u + at = 8 + 3×5 = 23 m/s.
Q86.For u = 5 m/s, a = 4 m/s², t = 6 s, displacement is:
- A.126 m
- B.98 m
- C.102 m
- D.30 m
Show answer
Correct answer: C. 102 m
s = ut + ½At² = 5×6 + 0.5×4×6² = 102 m.
Q87.Net force needed to give 8 kg mass an acceleration of 4 m/s² is:
- A.12 N
- B.32 N
- C.36 N
- D.28 N
Show answer
Correct answer: B. 32 N
F = ma = 8×4 = 32 N.
Q88.Work done when force 60 N moves a body 9 m in its direction is:
- A.540 J
- B.600 J
- C.480 J
- D.69 J
Show answer
Correct answer: A. 540 J
W = F×d = 60×9 = 540 J.
Q89.A body does 1200 J of work in 9 s. Its power is:
- A.266.67 W
- B.142.33 W
- C.128.33 W
- D.133.33 W
Show answer
Correct answer: D. 133.33 W
P = W/t = 1200/9 = 133.33 W.
Q90.A body of mass 9 kg moves at 8 m/s. Its momentum is:
- A.64 kg·m/s
- B.17 kg·m/s
- C.72 kg·m/s
- D.81 kg·m/s
Show answer
Correct answer: C. 72 kg·m/s
p = mv = 9×8 = 72 kg·m/s.
Q91.Kinetic energy of 3 kg body moving at 10 m/s is:
- A.147 J
- B.150 J
- C.30 J
- D.180 J
Show answer
Correct answer: B. 150 J
KE = ½mv² = 0.5×3×10² = 150 J.
Q92.Voltage across a 7 Ω resistor carrying 8 A current is:
- A.56 V
- B.63 V
- C.47 V
- D.17 V
Show answer
Correct answer: A. 56 V
V = IR = 8×7 = 56 V.
Q93.Two resistors 10 Ω and 10 Ω connected in series. Total resistance is:
- A.100 Ω
- B.0 Ω
- C.22 Ω
- D.20 Ω
Show answer
Correct answer: D. 20 Ω
Series: R = R₁ + R₂ = 10 + 10 = 20 Ω.
Q94.Power of a lens with focal length 80 cm is:
- A.2.25 D
- B.0.8 D
- C.1.25 D
- D.80 D
Show answer
Correct answer: C. 1.25 D
P = 1/f = 1/0.8 m = 1.25 D.
Q95.Wave speed for frequency 90 Hz and wavelength 3 m is:
- A.93 m/s
- B.270 m/s
- C.360 m/s
- D.240 m/s
Show answer
Correct answer: B. 270 m/s
v = fλ = 90×3 = 270 m/s.
Q96.Gravitational force when distance is doubled becomes:
- A.one-fourth
- B.half
- C.double
- D.unchanged
Show answer
Correct answer: A. one-fourth
F ∝ 1/r²; 2× distance → F/4.
Q97.A body starts with velocity 9 m/s and has acceleration 4 m/s². Its velocity after 6 s is:
- A.29 m/s
- B.37 m/s
- C.15 m/s
- D.33 m/s
Show answer
Correct answer: D. 33 m/s
v = u + at = 9 + 4×6 = 33 m/s.
Q98.For u = 6 m/s, a = 5 m/s², t = 7 s, displacement is:
- A.199.5 m
- B.159.5 m
- C.164.5 m
- D.42 m
Show answer
Correct answer: C. 164.5 m
s = ut + ½At² = 6×7 + 0.5×5×7² = 164.5 m.
Q99.Net force needed to give 9 kg mass an acceleration of 5 m/s² is:
- A.14 N
- B.45 N
- C.50 N
- D.40 N
Show answer
Correct answer: B. 45 N
F = ma = 9×5 = 45 N.
Q100.Work done when force 65 N moves a body 10 m in its direction is:
- A.650 J
- B.715 J
- C.585 J
- D.75 J
Show answer
Correct answer: A. 650 J
W = F×d = 65×10 = 650 J.
Q101.A body does 1250 J of work in 10 s. Its power is:
- A.250 W
- B.135 W
- C.120 W
- D.125 W
Show answer
Correct answer: D. 125 W
P = W/t = 1250/10 = 125 W.
Q102.A body of mass 10 kg moves at 9 m/s. Its momentum is:
- A.81 kg·m/s
- B.19 kg·m/s
- C.90 kg·m/s
- D.100 kg·m/s
Show answer
Correct answer: C. 90 kg·m/s
p = mv = 10×9 = 90 kg·m/s.
Q103.Kinetic energy of 4 kg body moving at 11 m/s is:
- A.238 J
- B.242 J
- C.44 J
- D.286 J
Show answer
Correct answer: B. 242 J
KE = ½mv² = 0.5×4×11² = 242 J.
Q104.Voltage across a 8 Ω resistor carrying 9 A current is:
- A.72 V
- B.80 V
- C.62 V
- D.19 V
Show answer
Correct answer: A. 72 V
V = IR = 9×8 = 72 V.
Q105.Two resistors 11 Ω and 11 Ω connected in series. Total resistance is:
- A.121 Ω
- B.0 Ω
- C.24 Ω
- D.22 Ω
Show answer
Correct answer: D. 22 Ω
Series: R = R₁ + R₂ = 11 + 11 = 22 Ω.
Q106.Power of a lens with focal length 90 cm is:
- A.2.11 D
- B.0.9 D
- C.1.11 D
- D.90 D
Show answer
Correct answer: C. 1.11 D
P = 1/f = 1/0.9 m = 1.11 D.
Q107.Wave speed for frequency 110 Hz and wavelength 4 m is:
- A.114 m/s
- B.440 m/s
- C.550 m/s
- D.400 m/s
Show answer
Correct answer: B. 440 m/s
v = fλ = 110×4 = 440 m/s.
Q108.Escape velocity from Earth's surface is approximately:
- A.11.2 km/s
- B.7.9 km/s
- C.3.0 km/s
- D.16.0 km/s
Show answer
Correct answer: A. 11.2 km/s
vᵉ = √(2gR) ≈ 11.2 km/s.
Q109.A body starts with velocity 2 m/s and has acceleration 5 m/s². Its velocity after 7 s is:
- A.32 m/s
- B.42 m/s
- C.9 m/s
- D.37 m/s
Show answer
Correct answer: D. 37 m/s
v = u + at = 2 + 5×7 = 37 m/s.
Q110.For u = 1 m/s, a = 6 m/s², t = 4 s, displacement is:
- A.76 m
- B.46 m
- C.52 m
- D.4 m
Show answer
Correct answer: C. 52 m
s = ut + ½At² = 1×4 + 0.5×6×4² = 52 m.
Q111.Net force needed to give 2 kg mass an acceleration of 6 m/s² is:
- A.8 N
- B.12 N
- C.18 N
- D.6 N
Show answer
Correct answer: B. 12 N
F = ma = 2×6 = 12 N.
Q112.Work done when force 10 N moves a body 3 m in its direction is:
- A.30 J
- B.40 J
- C.20 J
- D.13 J
Show answer
Correct answer: A. 30 J
W = F×d = 10×3 = 30 J.
Q113.A body does 1300 J of work in 5 s. Its power is:
- A.520 W
- B.265 W
- C.255 W
- D.260 W
Show answer
Correct answer: D. 260 W
P = W/t = 1300/5 = 260 W.
Q114.A body of mass 3 kg moves at 10 m/s. Its momentum is:
- A.20 kg·m/s
- B.13 kg·m/s
- C.30 kg·m/s
- D.33 kg·m/s
Show answer
Correct answer: C. 30 kg·m/s
p = mv = 3×10 = 30 kg·m/s.
Q115.Kinetic energy of 5 kg body moving at 4 m/s is:
- A.35 J
- B.40 J
- C.20 J
- D.60 J
Show answer
Correct answer: B. 40 J
KE = ½mv² = 0.5×5×4² = 40 J.
Q116.Voltage across a 9 Ω resistor carrying 2 A current is:
- A.18 V
- B.27 V
- C.15 V
- D.13 V
Show answer
Correct answer: A. 18 V
V = IR = 2×9 = 18 V.
Q117.Two resistors 4 Ω and 12 Ω connected in series. Total resistance is:
- A.48 Ω
- B.8 Ω
- C.18 Ω
- D.16 Ω
Show answer
Correct answer: D. 16 Ω
Series: R = R₁ + R₂ = 4 + 12 = 16 Ω.
Q118.Power of a lens with focal length 20 cm is:
- A.6 D
- B.0.2 D
- C.5 D
- D.20 D
Show answer
Correct answer: C. 5 D
P = 1/f = 1/0.2 m = 5 D.
Q119.Wave speed for frequency 130 Hz and wavelength 5 m is:
- A.135 m/s
- B.650 m/s
- C.780 m/s
- D.600 m/s
Show answer
Correct answer: B. 650 m/s
v = fλ = 130×5 = 650 m/s.
Q120.Orbital velocity of a satellite near Earth's surface is approximately:
- A.7.9 km/s
- B.11.2 km/s
- C.5.0 km/s
- D.3.0 km/s
Show answer
Correct answer: A. 7.9 km/s
First cosmic velocity ≈ 7.9 km/s.
Q121.If [H⁺] = 10⁻8 mol/L, the pH of the solution is:
- A.9
- B.6
- C.7
- D.8
Show answer
Correct answer: D. 8
pH = −log[H⁺] = −log(10⁻8) = 8.
Q122.Molar mass of Cl₂ is:
- A.70 g/mol
- B.72 g/mol
- C.71 g/mol
- D.35.5 g/mol
Show answer
Correct answer: C. 71 g/mol
Add atomic masses: molar mass of Cl₂ = 71 g/mol.
Q123.Oxidation state of Zn in ZnSO₄ is:
- A.+3
- B.+2
- C.+1
- D.0
Show answer
Correct answer: B. +2
SO₄=−2, Zn=+2.
Q124.Formula of manganese(II) oxide is:
- A.MnO
- B.Mn₂O₃
- C.MnO₂
- D.Mn₃O₄
Show answer
Correct answer: A. MnO
Mn(+2) and O(−2): MnO.
Q125.Colour of copper sulfate solution is:
- A.green
- B.colourless
- C.pink
- D.blue
Show answer
Correct answer: D. blue
CuSO₄ solution is blue due to [Cu(H₂O)₄]²⁺.
Q126.Formula of bleaching powder is:
- A.CaCl₂
- B.Ca(ClO₃)₂
- C.Ca(OCl)Cl
- D.CaO
Show answer
Correct answer: C. Ca(OCl)Cl
Bleaching powder = Ca(OCl)Cl.
Q127.Functional group in nitrobenzene is:
- A.−COOH
- B.−NO₂ (nitro)
- C.−NH₂ (amine)
- D.−OH
Show answer
Correct answer: B. −NO₂ (nitro)
C₆H₅NO₂ has a nitro group.
Q128.Which element in Period 2 has 2 valence electrons?
- A.Beryllium
- B.Magnesium
- C.Lithium
- D.Boron
Show answer
Correct answer: A. Beryllium
Be (Z=4): config 2,2 → Period 2, Group 2.
Q129.Number of moles in 40 g of NaOH (M = 40 g/mol) is:
- A.2
- B.3
- C.2.5
- D.1
Show answer
Correct answer: D. 1
n = mass/M = 40/40 = 1 mol.
Q130.Heisenberg uncertainty principle:
- A.energy is conserved
- B.photons have mass
- C.position and momentum cannot both be measured precisely simultaneously
- D.electrons move in fixed orbits
Show answer
Correct answer: C. position and momentum cannot both be measured precisely simultaneously
Δx·Δp ≥ h/(4π).
Q131.London dispersion forces are present in:
- A.metals only
- B.all molecules
- C.polar molecules only
- D.ionic compounds only
Show answer
Correct answer: B. all molecules
London forces arise from temporary dipoles in all molecules.
Q132.Greenhouse gas produced mainly from fossil fuel combustion is:
- A.CO₂
- B.O₂
- C.N₂
- D.H₂
Show answer
Correct answer: A. CO₂
CO₂ is the primary greenhouse gas from human activity.
Q133.If [H⁺] = 10⁻9 mol/L, the pH of the solution is:
- A.10
- B.5
- C.8
- D.9
Show answer
Correct answer: D. 9
pH = −log[H⁺] = −log(10⁻9) = 9.
Q134.Molar mass of SO₂ is:
- A.80 g/mol
- B.66 g/mol
- C.64 g/mol
- D.48 g/mol
Show answer
Correct answer: C. 64 g/mol
Add atomic masses: molar mass of SO₂ = 64 g/mol.
Q135.Oxidation state of Na in Na₂O₂ is:
- A.−1
- B.+1
- C.+2
- D.0
Show answer
Correct answer: B. +1
Na=+1; peroxide O=−1.
Q136.Formula of cobalt(II) chloride is:
- A.CoCl₂
- B.CoCl
- C.CoCl₃
- D.Co₂Cl₃
Show answer
Correct answer: A. CoCl₂
Co(+2) and Cl(−1): CoCl₂.
Q137.PbS precipitate colour with H₂S in lead acetate solution is:
- A.white
- B.yellow
- C.red
- D.black
Show answer
Correct answer: D. black
Pb(CH₃COO)₂ + H₂S → PbS↓(black).
Q138.Neutralisation of acid with base always produces:
- A.only water
- B.H₂ gas
- C.salt and water
- D.only salt
Show answer
Correct answer: C. salt and water
Acid + Base → Salt + Water.
Q139.Saponification reaction: ester + alkali gives:
- A.alkene + H₂O
- B.alcohol + soap (salt of fatty acid)
- C.ester + acid → alcohol
- D.alcohol + acid → ester
Show answer
Correct answer: B. alcohol + soap (salt of fatty acid)
RCOOR’ + NaOH → RCOONa + R’OH.
Q140.Which pair is in the same group of the periodic table?
- A.Na and K
- B.Na and Mg
- C.K and Ca
- D.Li and Be
Show answer
Correct answer: A. Na and K
Na and K are both in Group 1.
Q141.Number of moles in 117 g of NaCl (M = 58.5 g/mol) is:
- A.3
- B.1
- C.3.5
- D.2
Show answer
Correct answer: D. 2
n = mass/M = 117/58.5 = 2 mol.
Q142.3d subshell electrons of Fe²⁺ (Z=26) is:
- A.8
- B.5
- C.6
- D.4
Show answer
Correct answer: C. 6
Fe: [Ar]3d⁶ 4s²; Fe²⁺: [Ar]3d⁶.
Q143.Which has the shortest bond length?
- A.ionic bond
- B.triple bond
- C.single bond
- D.double bond
Show answer
Correct answer: B. triple bond
Bond order ↑ → bond length ↓.
Q144.Formula of washing soda is:
- A.Na₂CO₃·10H₂O
- B.NaHCO₃
- C.Na₂CO₃ (anhydrous)
- D.NaOH·10H₂O
Show answer
Correct answer: A. Na₂CO₃·10H₂O
Washing soda = Na₂CO₃·10H₂O.
Q145.If [H⁺] = 10⁻10 mol/L, the pH of the solution is:
- A.11
- B.4
- C.9
- D.10
Show answer
Correct answer: D. 10
pH = −log[H⁺] = −log(10⁻10) = 10.
Q146.Molar mass of NO₂ is:
- A.44 g/mol
- B.48 g/mol
- C.46 g/mol
- D.30 g/mol
Show answer
Correct answer: C. 46 g/mol
Add atomic masses: molar mass of NO₂ = 46 g/mol.
Q147.Oxidation state of carbon in CO is:
- A.0
- B.+2
- C.+4
- D.−2
Show answer
Correct answer: B. +2
O=−2, C=+2.
Q148.Formula of chromium(III) chloride is:
- A.CrCl₃
- B.CrCl₂
- C.Cr₂Cl₃
- D.CrCl
Show answer
Correct answer: A. CrCl₃
Cr(+3) needs 3 Cl(−1).
Q149.Gas used to test for presence of unsaturation in organic compound:
- A.H₂S
- B.NH₃
- C.Cl₂
- D.Br₂ water (bromine water)
Show answer
Correct answer: D. Br₂ water (bromine water)
Bromine water decolourises with alkenes/alkynes.
Q150.A buffer solution resists change in:
- A.colour
- B.volume
- C.pH
- D.temperature
Show answer
Correct answer: C. pH
Buffers maintain nearly constant pH.
Q151.Product of oxidation of primary alcohol using K₂Cr₂O₇/H⁺ is:
- A.ether
- B.aldehyde (then carboxylic acid)
- C.ketone
- D.ester
Show answer
Correct answer: B. aldehyde (then carboxylic acid)
Primary alcohol → aldehyde → carboxylic acid on oxidation.
Q152.Atomic number of calcium is:
- A.20
- B.40
- C.19
- D.21
Show answer
Correct answer: A. 20
Ca has 20 protons.
Q153.Number of moles in 84 g of CO (M = 28 g/mol) is:
- A.4
- B.2
- C.4.5
- D.3
Show answer
Correct answer: D. 3
n = mass/M = 84/28 = 3 mol.
Q154.Bohr model accurately explains atomic spectra of:
- A.all metals
- B.noble gases only
- C.hydrogen-like atoms
- D.all atoms
Show answer
Correct answer: C. hydrogen-like atoms
Bohr model works for H-like (one-electron) atoms.
Q155.Bond formed by sharing of electrons is:
- A.hydrogen bond
- B.covalent bond
- C.ionic bond
- D.metallic bond
Show answer
Correct answer: B. covalent bond
Covalent bonds involve electron sharing.
Q156.Magnesia is:
- A.MgO
- B.Mg(OH)₂
- C.MgSO₄
- D.MgCO₃
Show answer
Correct answer: A. MgO
Magnesia = magnesium oxide (MgO).
Q157.If [H⁺] = 10⁻11 mol/L, the pH of the solution is:
- A.12
- B.3
- C.10
- D.11
Show answer
Correct answer: D. 11
pH = −log[H⁺] = −log(10⁻11) = 11.
Q158.Molar mass of KOH is:
- A.55 g/mol
- B.58 g/mol
- C.56 g/mol
- D.39 g/mol
Show answer
Correct answer: C. 56 g/mol
Add atomic masses: molar mass of KOH = 56 g/mol.
Q159.Oxidation state of oxygen in OF₂ is:
- A.+1
- B.+2
- C.−2
- D.0
Show answer
Correct answer: B. +2
F=−1(×2); O is less electronegative → O=+2.
Q160.Formula of potassium permanganate is:
- A.KMnO₄
- B.K₂MnO₄
- C.KMnO₃
- D.K₂Mn₂O₇
Show answer
Correct answer: A. KMnO₄
K(+1) and MnO₄⁻: KMnO₄.
Q161.Product of combustion of methane (complete) is:
- A.CO and H₂O
- B.CO₂ and H₂
- C.C and H₂O
- D.CO₂ and H₂O
Show answer
Correct answer: D. CO₂ and H₂O
CH₄ + 2O₂ → CO₂ + 2H₂O.
Q162.Which property increases across a period?
- A.metallic character
- B.ionisation energy decreases
- C.electronegativity
- D.atomic radius
Show answer
Correct answer: C. electronegativity
Electronegativity increases across a period.
Q163.Functional group in chloroethane is:
- A.−COOH
- B.−Cl (halo)
- C.−OH
- D.−NH₂
Show answer
Correct answer: B. −Cl (halo)
C₂H₅Cl is a haloalkane.
Q164.Which element has the highest electronegativity?
- A.Fluorine
- B.Oxygen
- C.Chlorine
- D.Nitrogen
Show answer
Correct answer: A. Fluorine
Fluorine has highest electronegativity (Pauling scale: 3.98).
Q165.Number of moles in 128 g of O₂ (M = 32 g/mol) is:
- A.5
- B.3
- C.5.5
- D.4
Show answer
Correct answer: D. 4
n = mass/M = 128/32 = 4 mol.
Q166.Electronic configuration 2,8,18,1 corresponds to:
- A.Nickel (Ni)
- B.Iron (Fe)
- C.Copper (Cu, Z=29)
- D.Zinc (Zn)
Show answer
Correct answer: C. Copper (Cu, Z=29)
2+8+18+1=29 → Cu.
Q167.Force binding atoms in a metallic lattice is:
- A.van der Waals
- B.metallic bond (electron sea)
- C.ionic attraction
- D.covalent bond
Show answer
Correct answer: B. metallic bond (electron sea)
Delocalised electrons form metallic bonds.
Q168.Substance used to test for starch is:
- A.iodine solution
- B.Fehling’s solution
- C.Tollens’ reagent
- D.bromine water
Show answer
Correct answer: A. iodine solution
Iodine turns blue-black with starch.
Q169.If [H⁺] = 10⁻12 mol/L, the pH of the solution is:
- A.13
- B.2
- C.11
- D.12
Show answer
Correct answer: D. 12
pH = −log[H⁺] = −log(10⁻12) = 12.
Q170.Molar mass of Na₂CO₃ is:
- A.100 g/mol
- B.108 g/mol
- C.106 g/mol
- D.62 g/mol
Show answer
Correct answer: C. 106 g/mol
Add atomic masses: molar mass of Na₂CO₃ = 106 g/mol.
Q171.Oxidation state of Cl in ClO₃⁻ is:
- A.−1
- B.+5
- C.+3
- D.+7
Show answer
Correct answer: B. +5
O=−2(×3)=−6; charge=−1; Cl=+5.
Q172.Formula of ammonium chloride is:
- A.NH₄Cl
- B.N₂H₄Cl
- C.NH₃Cl
- D.(NH₄)₂Cl
Show answer
Correct answer: A. NH₄Cl
NH₄⁺(+1) and Cl(−1): NH₄Cl.
Q173.Aqua regia dissolves gold because:
- A.gold is a weak metal
- B.gold is soluble in HCl alone
- C.gold reacts with water
- D.it is a powerful oxidising and complexing mixture
Show answer
Correct answer: D. it is a powerful oxidising and complexing mixture
Conc. HNO₃ + 3 conc. HCl oxidise and complex gold.
Q174.Antacid tablets contain:
- A.NaHSO₄
- B.Na₂CO₃ solution
- C.Mg(OH)₂ or Al(OH)₃
- D.HCl
Show answer
Correct answer: C. Mg(OH)₂ or Al(OH)₃
Antacids are mild bases that neutralise excess stomach acid.
Q175.Compound formed by treating carboxylic acid with SOCl₂ is:
- A.amide
- B.acid chloride
- C.ester
- D.anhydride
Show answer
Correct answer: B. acid chloride
RCOOH + SOCl₂ → RCOCl (acid chloride) + SO₂ + HCl.
Q176.Symbol of silver is:
- A.Ag
- B.Si
- C.Au
- D.Sr
Show answer
Correct answer: A. Ag
Ag from Latin ‘argentum’ (silver).
Q177.Number of moles in 355 g of Cl₂ (M = 71 g/mol) is:
- A.6
- B.4
- C.6.5
- D.5
Show answer
Correct answer: D. 5
n = mass/M = 355/71 = 5 mol.
Q178.Electronic configuration 2,2 corresponds to:
- A.Boron (B)
- B.Helium (He)
- C.Beryllium (Be)
- D.Lithium (Li)
Show answer
Correct answer: C. Beryllium (Be)
2+2=4 → Be (Z=4).
Q179.Number of lone pairs on oxygen in H₂O is:
- A.3
- B.2
- C.0
- D.1
Show answer
Correct answer: B. 2
O has 6 valence electrons; 2 used in bonds, 4 in 2 lone pairs.
Q180.Chemical name of slaked lime is:
- A.calcium hydroxide
- B.calcium oxide
- C.calcium carbonate
- D.calcium sulfate
Show answer
Correct answer: A. calcium hydroxide
Slaked lime = Ca(OH)₂.