COMEDK Practice Set 3
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 3: all 180 questions with answers
Try each question first, then open “Show answer” to check the correct option and explanation.
Q1.Solve for x: 5x + 6 = 21.
- A.4
- B.2
- C.5
- D.3
Show answer
Correct answer: D. 3
Subtract 6 from both sides: 5x = 15. Divide by 5: x = 3.
Q2.One root of x² − 12x + 35 = 0 is 5. The other root is:
- A.6
- B.12
- C.7
- D.8
Show answer
Correct answer: C. 7
Product of roots = 35. Other root = 35 ÷ 5 = 7.
Q3.The 8th term of an AP with first term 2 and common difference 5 is:
- A.40
- B.37
- C.32
- D.42
Show answer
Correct answer: B. 37
aₙ = a + (n−1)d = 2 + 7×5 = 37.
Q4.Slope of the line through (5, 5) and (8, 17) is:
- A.4
- B.5
- C.3
- D.6
Show answer
Correct answer: A. 4
Slope = (17−5) ÷ (8−5) = 12 ÷ 3 = 4.
Q5.Value of sin 60° is:
- A.1/2
- B.1
- C.1/√2
- D.√3/2
Show answer
Correct answer: D. √3/2
sin 60° = √3/2.
Q6.A bag contains 5 red and 6 blue balls. Probability of drawing a red ball is:
- A.5/10
- B.7/12
- C.5/11
- D.6/12
Show answer
Correct answer: C. 5/11
P(red) = 5/11.
Q7.Determinant of matrix [[5, 1], [4, 5]] is:
- A.19
- B.21
- C.26
- D.18
Show answer
Correct answer: B. 21
det = ad − bc = 5×5 − 1×4 = 21.
Q8.Evaluate: log₂ₐₑₒₓ5(5^5) [log base 5].
- A.5
- B.6
- C.4
- D.25
Show answer
Correct answer: A. 5
logₐ(a^n) = n, so log_5(5^5) = 5.
Q9.Find 8P3.
- A.112
- B.342
- C.330
- D.336
Show answer
Correct answer: D. 336
8P3 = 8!/(8−3)! = 8×7×6 = 336.
Q10.Find 8C2.
- A.31
- B.25
- C.28
- D.16
Show answer
Correct answer: C. 28
nC2 = n(n−1)/2 = 8×7/2 = 28.
Q11.Simple interest on Rs 2500 at 5% p.a. for 4 years is:
- A.Rs 1000
- B.Rs 500
- C.Rs 700
- D.Rs 400
Show answer
Correct answer: B. Rs 500
SI = P×R×T/100 = 2500×5×4/100 = Rs 500.
Q12.Area of a triangle with base 6 cm and height 5 cm is:
- A.15 cm²
- B.30 cm²
- C.21 cm²
- D.9 cm²
Show answer
Correct answer: A. 15 cm²
Area = (1/2) × base × height = (1/2) × 6 × 5 = 15 cm².
Q13.Solve for x: 6x + 7 = 31.
- A.5
- B.3
- C.6
- D.4
Show answer
Correct answer: D. 4
Subtract 7 from both sides: 6x = 24. Divide by 6: x = 4.
Q14.One root of x² − 15x + 54 = 0 is 6. The other root is:
- A.8
- B.15
- C.9
- D.10
Show answer
Correct answer: C. 9
Product of roots = 54. Other root = 54 ÷ 6 = 9.
Q15.The 9th term of an AP with first term 3 and common difference 6 is:
- A.55
- B.51
- C.45
- D.57
Show answer
Correct answer: B. 51
aₙ = a + (n−1)d = 3 + 8×6 = 51.
Q16.Slope of the line through (6, 6) and (9, 21) is:
- A.5
- B.6
- C.4
- D.7
Show answer
Correct answer: A. 5
Slope = (21−6) ÷ (9−6) = 15 ÷ 3 = 5.
Q17.Value of tan 30° is:
- A.√3
- B.1
- C.1/2
- D.1/√3
Show answer
Correct answer: D. 1/√3
tan 30° = 1/√3.
Q18.A bag contains 6 red and 7 blue balls. Probability of drawing a red ball is:
- A.6/12
- B.8/14
- C.6/13
- D.7/14
Show answer
Correct answer: C. 6/13
P(red) = 6/13.
Q19.Determinant of matrix [[6, 2], [5, 6]] is:
- A.22
- B.26
- C.31
- D.23
Show answer
Correct answer: B. 26
det = ad − bc = 6×6 − 2×5 = 26.
Q20.Evaluate: log₂ₐₑₒₓ10(10^6) [log base 10].
- A.6
- B.7
- C.5
- D.60
Show answer
Correct answer: A. 6
logₐ(a^n) = n, so log_10(10^6) = 6.
Q21.Find 9P4.
- A.756
- B.3032
- C.3016
- D.3024
Show answer
Correct answer: D. 3024
9P4 = 9!/(9−4)! = 9×8×7×6 = 3024.
Q22.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.
Q23.Simple interest on Rs 2700 at 6% p.a. for 5 years is:
- A.Rs 1620
- B.Rs 810
- C.Rs 1110
- D.Rs 660
Show answer
Correct answer: B. Rs 810
SI = P×R×T/100 = 2700×6×5/100 = Rs 810.
Q24.Area of a triangle with base 7 cm and height 6 cm is:
- A.21 cm²
- B.42 cm²
- C.27 cm²
- D.15 cm²
Show answer
Correct answer: A. 21 cm²
Area = (1/2) × base × height = (1/2) × 7 × 6 = 21 cm².
Q25.Solve for x: 7x + 8 = 43.
- A.6
- B.4
- C.7
- D.5
Show answer
Correct answer: D. 5
Subtract 8 from both sides: 7x = 35. Divide by 7: x = 5.
Q26.One root of x² − 18x + 77 = 0 is 7. The other root is:
- A.10
- B.18
- C.11
- D.12
Show answer
Correct answer: C. 11
Product of roots = 77. Other root = 77 ÷ 7 = 11.
Q27.The 10th term of an AP with first term 4 and common difference 7 is:
- A.72
- B.67
- C.60
- D.74
Show answer
Correct answer: B. 67
aₙ = a + (n−1)d = 4 + 9×7 = 67.
Q28.Slope of the line through (1, 7) and (4, 25) is:
- A.6
- B.7
- C.5
- D.8
Show answer
Correct answer: A. 6
Slope = (25−7) ÷ (4−1) = 18 ÷ 3 = 6.
Q29.Value of tan 60° is:
- A.1
- B.1/√3
- C.2
- D.√3
Show answer
Correct answer: D. √3
tan 60° = √3.
Q30.A bag contains 7 red and 8 blue balls. Probability of drawing a red ball is:
- A.7/14
- B.9/16
- C.7/15
- D.8/16
Show answer
Correct answer: C. 7/15
P(red) = 7/15.
Q31.Determinant of matrix [[7, 3], [2, 7]] is:
- A.21
- B.43
- C.48
- D.40
Show answer
Correct answer: B. 43
det = ad − bc = 7×7 − 3×2 = 43.
Q32.Evaluate: log₂ₐₑₒₓ2(2^7) [log base 2].
- A.7
- B.8
- C.6
- D.14
Show answer
Correct answer: A. 7
logₐ(a^n) = n, so log_2(2^7) = 7.
Q33.Find 10P2.
- A.45
- B.94
- C.86
- D.90
Show answer
Correct answer: D. 90
10P2 = 10!/(10−2)! = 10×9 = 90.
Q34.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.
Q35.Simple interest on Rs 2900 at 7% p.a. for 2 years is:
- A.Rs 812
- B.Rs 406
- C.Rs 546
- D.Rs 336
Show answer
Correct answer: B. Rs 406
SI = P×R×T/100 = 2900×7×2/100 = Rs 406.
Q36.Area of a triangle with base 8 cm and height 7 cm is:
- A.28 cm²
- B.56 cm²
- C.34 cm²
- D.22 cm²
Show answer
Correct answer: A. 28 cm²
Area = (1/2) × base × height = (1/2) × 8 × 7 = 28 cm².
Q37.Solve for x: 8x + 9 = 57.
- A.7
- B.5
- C.8
- D.6
Show answer
Correct answer: D. 6
Subtract 9 from both sides: 8x = 48. Divide by 8: x = 6.
Q38.One root of x² − 21x + 104 = 0 is 8. The other root is:
- A.12
- B.21
- C.13
- D.14
Show answer
Correct answer: C. 13
Product of roots = 104. Other root = 104 ÷ 8 = 13.
Q39.The 11th term of an AP with first term 5 and common difference 8 is:
- A.91
- B.85
- C.77
- D.93
Show answer
Correct answer: B. 85
aₙ = a + (n−1)d = 5 + 10×8 = 85.
Q40.Slope of the line through (2, 8) and (5, 29) is:
- A.7
- B.8
- C.6
- D.9
Show answer
Correct answer: A. 7
Slope = (29−8) ÷ (5−2) = 21 ÷ 3 = 7.
Q41.Value of sin 120° is:
- A.1/2
- B.−√3/2
- C.1
- D.√3/2
Show answer
Correct answer: D. √3/2
sin 120° = sin 60° = √3/2.
Q42.A bag contains 8 red and 9 blue balls. Probability of drawing a red ball is:
- A.8/16
- B.10/18
- C.8/17
- D.9/18
Show answer
Correct answer: C. 8/17
P(red) = 8/17.
Q43.Determinant of matrix [[8, 4], [3, 8]] is:
- A.24
- B.52
- C.57
- D.49
Show answer
Correct answer: B. 52
det = ad − bc = 8×8 − 4×3 = 52.
Q44.Evaluate: log₂ₐₑₒₓ3(3^8) [log base 3].
- A.8
- B.9
- C.7
- D.24
Show answer
Correct answer: A. 8
logₐ(a^n) = n, so log_3(3^8) = 8.
Q45.Find 11P3.
- A.330
- B.996
- C.984
- D.990
Show answer
Correct answer: D. 990
11P3 = 11!/(11−3)! = 11×10×9 = 990.
Q46.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.
Q47.Simple interest on Rs 3100 at 8% p.a. for 3 years is:
- A.Rs 1488
- B.Rs 744
- C.Rs 984
- D.Rs 624
Show answer
Correct answer: B. Rs 744
SI = P×R×T/100 = 3100×8×3/100 = Rs 744.
Q48.Area of a triangle with base 9 cm and height 8 cm is:
- A.36 cm²
- B.72 cm²
- C.42 cm²
- D.30 cm²
Show answer
Correct answer: A. 36 cm²
Area = (1/2) × base × height = (1/2) × 9 × 8 = 36 cm².
Q49.Solve for x: 2x + 10 = 24.
- A.8
- B.6
- C.9
- D.7
Show answer
Correct answer: D. 7
Subtract 10 from both sides: 2x = 14. Divide by 2: x = 7.
Q50.One root of x² − 24x + 135 = 0 is 9. The other root is:
- A.14
- B.24
- C.15
- D.16
Show answer
Correct answer: C. 15
Product of roots = 135. Other root = 135 ÷ 9 = 15.
Q51.The 12th term of an AP with first term 6 and common difference 2 is:
- A.35
- B.28
- C.26
- D.30
Show answer
Correct answer: B. 28
aₙ = a + (n−1)d = 6 + 11×2 = 28.
Q52.Slope of the line through (3, 2) and (6, 26) is:
- A.8
- B.9
- C.7
- D.10
Show answer
Correct answer: A. 8
Slope = (26−2) ÷ (6−3) = 24 ÷ 3 = 8.
Q53.Value of cos 120° is:
- A.1/2
- B.√3/2
- C.−1
- D.−1/2
Show answer
Correct answer: D. −1/2
cos 120° = −cos 60° = −1/2.
Q54.A bag contains 9 red and 10 blue balls. Probability of drawing a red ball is:
- A.9/18
- B.11/20
- C.9/19
- D.10/20
Show answer
Correct answer: C. 9/19
P(red) = 9/19.
Q55.Determinant of matrix [[2, 5], [4, 9]] is:
- A.20
- B.-2
- C.3
- D.-5
Show answer
Correct answer: B. -2
det = ad − bc = 2×9 − 5×4 = -2.
Q56.Evaluate: log₂ₐₑₒₓ5(5^2) [log base 5].
- A.2
- B.3
- C.1
- D.10
Show answer
Correct answer: A. 2
logₐ(a^n) = n, so log_5(5^2) = 2.
Q57.Find 12P4.
- A.2970
- B.11888
- C.11872
- D.11880
Show answer
Correct answer: D. 11880
12P4 = 12!/(12−4)! = 12×11×10×9 = 11880.
Q58.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.
Q59.Simple interest on Rs 3300 at 9% p.a. for 4 years is:
- A.Rs 2376
- B.Rs 1188
- C.Rs 1548
- D.Rs 1008
Show answer
Correct answer: B. Rs 1188
SI = P×R×T/100 = 3300×9×4/100 = Rs 1188.
Q60.Area of a triangle with base 10 cm and height 9 cm is:
- A.45 cm²
- B.90 cm²
- C.51 cm²
- D.39 cm²
Show answer
Correct answer: A. 45 cm²
Area = (1/2) × base × height = (1/2) × 10 × 9 = 45 cm².
Q61.A body starts with velocity 4 m/s and has acceleration 5 m/s². Its velocity after 3 s is:
- A.14 m/s
- B.24 m/s
- C.7 m/s
- D.19 m/s
Show answer
Correct answer: D. 19 m/s
v = u + at = 4 + 5×3 = 19 m/s.
Q62.For u = 5 m/s, a = 2 m/s², t = 6 s, displacement is:
- A.78 m
- B.64 m
- C.66 m
- D.30 m
Show answer
Correct answer: C. 66 m
s = ut + ½At² = 5×6 + 0.5×2×6² = 66 m.
Q63.Net force needed to give 4 kg mass an acceleration of 6 m/s² is:
- A.10 N
- B.24 N
- C.30 N
- D.18 N
Show answer
Correct answer: B. 24 N
F = ma = 4×6 = 24 N.
Q64.Work done when force 60 N moves a body 5 m in its direction is:
- A.300 J
- B.360 J
- C.240 J
- D.65 J
Show answer
Correct answer: A. 300 J
W = F×d = 60×5 = 300 J.
Q65.A body does 600 J of work in 9 s. Its power is:
- A.133.33 W
- B.75.67 W
- C.61.67 W
- D.66.67 W
Show answer
Correct answer: D. 66.67 W
P = W/t = 600/9 = 66.67 W.
Q66.A body of mass 5 kg moves at 5 m/s. Its momentum is:
- A.20 kg·m/s
- B.10 kg·m/s
- C.25 kg·m/s
- D.30 kg·m/s
Show answer
Correct answer: C. 25 kg·m/s
p = mv = 5×5 = 25 kg·m/s.
Q67.Kinetic energy of 5 kg body moving at 6 m/s is:
- A.85 J
- B.90 J
- C.30 J
- D.120 J
Show answer
Correct answer: B. 90 J
KE = ½mv² = 0.5×5×6² = 90 J.
Q68.Voltage across a 4 Ω resistor carrying 4 A current is:
- A.16 V
- B.20 V
- C.11 V
- D.10 V
Show answer
Correct answer: A. 16 V
V = IR = 4×4 = 16 V.
Q69.Two resistors 6 Ω and 7 Ω connected in series. Total resistance is:
- A.42 Ω
- B.1 Ω
- C.15 Ω
- D.13 Ω
Show answer
Correct answer: D. 13 Ω
Series: R = R₁ + R₂ = 6 + 7 = 13 Ω.
Q70.Power of a lens with focal length 40 cm is:
- A.3.5 D
- B.0.4 D
- C.2.5 D
- D.40 D
Show answer
Correct answer: C. 2.5 D
P = 1/f = 1/0.4 m = 2.5 D.
Q71.Wave speed for frequency 50 Hz and wavelength 5 m is:
- A.55 m/s
- B.250 m/s
- C.300 m/s
- D.200 m/s
Show answer
Correct answer: B. 250 m/s
v = fλ = 50×5 = 250 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 5 m/s and has acceleration 6 m/s². Its velocity after 4 s is:
- A.23 m/s
- B.35 m/s
- C.9 m/s
- D.29 m/s
Show answer
Correct answer: D. 29 m/s
v = u + at = 5 + 6×4 = 29 m/s.
Q74.For u = 6 m/s, a = 3 m/s², t = 7 s, displacement is:
- A.136.5 m
- B.112.5 m
- C.115.5 m
- D.42 m
Show answer
Correct answer: C. 115.5 m
s = ut + ½At² = 6×7 + 0.5×3×7² = 115.5 m.
Q75.Net force needed to give 5 kg mass an acceleration of 7 m/s² is:
- A.12 N
- B.35 N
- C.42 N
- D.28 N
Show answer
Correct answer: B. 35 N
F = ma = 5×7 = 35 N.
Q76.Work done when force 65 N moves a body 6 m in its direction is:
- A.390 J
- B.455 J
- C.325 J
- D.71 J
Show answer
Correct answer: A. 390 J
W = F×d = 65×6 = 390 J.
Q77.A body does 650 J of work in 10 s. Its power is:
- A.130 W
- B.75 W
- C.60 W
- D.65 W
Show answer
Correct answer: D. 65 W
P = W/t = 650/10 = 65 W.
Q78.A body of mass 6 kg moves at 6 m/s. Its momentum is:
- A.30 kg·m/s
- B.12 kg·m/s
- C.36 kg·m/s
- D.42 kg·m/s
Show answer
Correct answer: C. 36 kg·m/s
p = mv = 6×6 = 36 kg·m/s.
Q79.Kinetic energy of 6 kg body moving at 7 m/s is:
- A.141 J
- B.147 J
- C.42 J
- D.189 J
Show answer
Correct answer: B. 147 J
KE = ½mv² = 0.5×6×7² = 147 J.
Q80.Voltage across a 5 Ω resistor carrying 5 A current is:
- A.25 V
- B.30 V
- C.19 V
- D.12 V
Show answer
Correct answer: A. 25 V
V = IR = 5×5 = 25 V.
Q81.Two resistors 7 Ω and 8 Ω connected in series. Total resistance is:
- A.56 Ω
- B.1 Ω
- C.17 Ω
- D.15 Ω
Show answer
Correct answer: D. 15 Ω
Series: R = R₁ + R₂ = 7 + 8 = 15 Ω.
Q82.Power of a lens with focal length 50 cm is:
- A.3 D
- B.0.5 D
- C.2 D
- D.50 D
Show answer
Correct answer: C. 2 D
P = 1/f = 1/0.5 m = 2 D.
Q83.Wave speed for frequency 70 Hz and wavelength 6 m is:
- A.76 m/s
- B.420 m/s
- C.490 m/s
- D.360 m/s
Show answer
Correct answer: B. 420 m/s
v = fλ = 70×6 = 420 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 6 m/s and has acceleration 7 m/s². Its velocity after 5 s is:
- A.34 m/s
- B.48 m/s
- C.11 m/s
- D.41 m/s
Show answer
Correct answer: D. 41 m/s
v = u + at = 6 + 7×5 = 41 m/s.
Q86.For u = 1 m/s, a = 4 m/s², t = 4 s, displacement is:
- A.52 m
- B.32 m
- C.36 m
- D.4 m
Show answer
Correct answer: C. 36 m
s = ut + ½At² = 1×4 + 0.5×4×4² = 36 m.
Q87.Net force needed to give 6 kg mass an acceleration of 8 m/s² is:
- A.14 N
- B.48 N
- C.56 N
- D.40 N
Show answer
Correct answer: B. 48 N
F = ma = 6×8 = 48 N.
Q88.Work done when force 10 N moves a body 7 m in its direction is:
- A.70 J
- B.80 J
- C.60 J
- D.17 J
Show answer
Correct answer: A. 70 J
W = F×d = 10×7 = 70 J.
Q89.A body does 700 J of work in 5 s. Its power is:
- A.280 W
- B.145 W
- C.135 W
- D.140 W
Show answer
Correct answer: D. 140 W
P = W/t = 700/5 = 140 W.
Q90.A body of mass 7 kg moves at 7 m/s. Its momentum is:
- A.42 kg·m/s
- B.14 kg·m/s
- C.49 kg·m/s
- D.56 kg·m/s
Show answer
Correct answer: C. 49 kg·m/s
p = mv = 7×7 = 49 kg·m/s.
Q91.Kinetic energy of 7 kg body moving at 8 m/s is:
- A.217 J
- B.224 J
- C.56 J
- D.280 J
Show answer
Correct answer: B. 224 J
KE = ½mv² = 0.5×7×8² = 224 J.
Q92.Voltage across a 6 Ω resistor carrying 6 A current is:
- A.36 V
- B.42 V
- C.29 V
- D.14 V
Show answer
Correct answer: A. 36 V
V = IR = 6×6 = 36 V.
Q93.Two resistors 8 Ω and 9 Ω connected in series. Total resistance is:
- A.72 Ω
- B.1 Ω
- C.19 Ω
- D.17 Ω
Show answer
Correct answer: D. 17 Ω
Series: R = R₁ + R₂ = 8 + 9 = 17 Ω.
Q94.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.
Q95.Wave speed for frequency 90 Hz and wavelength 7 m is:
- A.97 m/s
- B.630 m/s
- C.720 m/s
- D.560 m/s
Show answer
Correct answer: B. 630 m/s
v = fλ = 90×7 = 630 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 7 m/s and has acceleration 8 m/s². Its velocity after 6 s is:
- A.47 m/s
- B.63 m/s
- C.13 m/s
- D.55 m/s
Show answer
Correct answer: D. 55 m/s
v = u + at = 7 + 8×6 = 55 m/s.
Q98.For u = 2 m/s, a = 5 m/s², t = 5 s, displacement is:
- A.97.5 m
- B.67.5 m
- C.72.5 m
- D.10 m
Show answer
Correct answer: C. 72.5 m
s = ut + ½At² = 2×5 + 0.5×5×5² = 72.5 m.
Q99.Net force needed to give 7 kg mass an acceleration of 9 m/s² is:
- A.16 N
- B.63 N
- C.72 N
- D.54 N
Show answer
Correct answer: B. 63 N
F = ma = 7×9 = 63 N.
Q100.Work done when force 15 N moves a body 8 m in its direction is:
- A.120 J
- B.135 J
- C.105 J
- D.23 J
Show answer
Correct answer: A. 120 J
W = F×d = 15×8 = 120 J.
Q101.A body does 750 J of work in 6 s. Its power is:
- A.250 W
- B.131 W
- C.120 W
- D.125 W
Show answer
Correct answer: D. 125 W
P = W/t = 750/6 = 125 W.
Q102.A body of mass 8 kg moves at 8 m/s. Its momentum is:
- A.56 kg·m/s
- B.16 kg·m/s
- C.64 kg·m/s
- D.72 kg·m/s
Show answer
Correct answer: C. 64 kg·m/s
p = mv = 8×8 = 64 kg·m/s.
Q103.Kinetic energy of 8 kg body moving at 9 m/s is:
- A.316 J
- B.324 J
- C.72 J
- D.396 J
Show answer
Correct answer: B. 324 J
KE = ½mv² = 0.5×8×9² = 324 J.
Q104.Voltage across a 7 Ω resistor carrying 7 A current is:
- A.49 V
- B.56 V
- C.41 V
- D.16 V
Show answer
Correct answer: A. 49 V
V = IR = 7×7 = 49 V.
Q105.Two resistors 9 Ω and 10 Ω connected in series. Total resistance is:
- A.90 Ω
- B.1 Ω
- C.21 Ω
- D.19 Ω
Show answer
Correct answer: D. 19 Ω
Series: R = R₁ + R₂ = 9 + 10 = 19 Ω.
Q106.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.
Q107.Wave speed for frequency 110 Hz and wavelength 8 m is:
- A.118 m/s
- B.880 m/s
- C.990 m/s
- D.800 m/s
Show answer
Correct answer: B. 880 m/s
v = fλ = 110×8 = 880 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 8 m/s and has acceleration 2 m/s². Its velocity after 7 s is:
- A.20 m/s
- B.24 m/s
- C.15 m/s
- D.22 m/s
Show answer
Correct answer: D. 22 m/s
v = u + at = 8 + 2×7 = 22 m/s.
Q110.For u = 3 m/s, a = 6 m/s², t = 6 s, displacement is:
- A.162 m
- B.120 m
- C.126 m
- D.18 m
Show answer
Correct answer: C. 126 m
s = ut + ½At² = 3×6 + 0.5×6×6² = 126 m.
Q111.Net force needed to give 8 kg mass an acceleration of 3 m/s² is:
- A.11 N
- B.24 N
- C.27 N
- D.21 N
Show answer
Correct answer: B. 24 N
F = ma = 8×3 = 24 N.
Q112.Work done when force 20 N moves a body 9 m in its direction is:
- A.180 J
- B.200 J
- C.160 J
- D.29 J
Show answer
Correct answer: A. 180 J
W = F×d = 20×9 = 180 J.
Q113.A body does 800 J of work in 7 s. Its power is:
- A.228.57 W
- B.121.29 W
- C.109.29 W
- D.114.29 W
Show answer
Correct answer: D. 114.29 W
P = W/t = 800/7 = 114.29 W.
Q114.A body of mass 9 kg moves at 9 m/s. Its momentum is:
- A.72 kg·m/s
- B.18 kg·m/s
- C.81 kg·m/s
- D.90 kg·m/s
Show answer
Correct answer: C. 81 kg·m/s
p = mv = 9×9 = 81 kg·m/s.
Q115.Kinetic energy of 2 kg body moving at 10 m/s is:
- A.98 J
- B.100 J
- C.20 J
- D.120 J
Show answer
Correct answer: B. 100 J
KE = ½mv² = 0.5×2×10² = 100 J.
Q116.Voltage across a 8 Ω resistor carrying 8 A current is:
- A.64 V
- B.72 V
- C.55 V
- D.18 V
Show answer
Correct answer: A. 64 V
V = IR = 8×8 = 64 V.
Q117.Two resistors 10 Ω and 11 Ω connected in series. Total resistance is:
- A.110 Ω
- B.1 Ω
- C.23 Ω
- D.21 Ω
Show answer
Correct answer: D. 21 Ω
Series: R = R₁ + R₂ = 10 + 11 = 21 Ω.
Q118.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.
Q119.Wave speed for frequency 130 Hz and wavelength 2 m is:
- A.132 m/s
- B.260 m/s
- C.390 m/s
- D.240 m/s
Show answer
Correct answer: B. 260 m/s
v = fλ = 130×2 = 260 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⁺] = 10⁻11 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.
Q122.Molar mass of MgO is:
- A.32 g/mol
- B.44 g/mol
- C.40 g/mol
- D.24 g/mol
Show answer
Correct answer: C. 40 g/mol
Add atomic masses: molar mass of MgO = 40 g/mol.
Q123.Oxidation state of sulfur in SO₂ is:
- A.−2
- B.+4
- C.+6
- D.+2
Show answer
Correct answer: B. +4
2O(−2)+S=0 → S=+4.
Q124.Formula of iron(II) sulfate is:
- A.FeSO₄
- B.Fe₂SO₄
- C.Fe(SO₄)₂
- D.FeSO₃
Show answer
Correct answer: A. FeSO₄
Fe(+2) and SO₄²⁻: FeSO₄.
Q125.Gas produced when CaC₂ reacts with water is:
- A.methane
- B.ethane
- C.propane
- D.acetylene (ethyne)
Show answer
Correct answer: D. acetylene (ethyne)
CaC₂ + 2H₂O → Ca(OH)₂ + C₂H₂↑.
Q126.pH of 0.1 M HCl solution is:
- A.7
- B.0
- C.1
- D.3
Show answer
Correct answer: C. 1
[H⁺]=0.1=10⁻¹; pH=1.
Q127.General formula of alkynes is:
- A.CₙHₙ
- B.CₙH₂ₙ₋₂
- C.CₙH₂ₙ₊₂
- D.CₙH₂ₙ
Show answer
Correct answer: B. CₙH₂ₙ₋₂
Alkynes: CₙH₂ₙ₋₂ (one triple bond).
Q128.Which is a metalloid?
- A.Silicon
- B.Sulphur
- C.Phosphorus
- D.Selenium
Show answer
Correct answer: A. Silicon
Silicon is a common metalloid.
Q129.Number of moles in 56 g of CaO (M = 56 g/mol) is:
- A.2
- B.3
- C.2.5
- D.1
Show answer
Correct answer: D. 1
n = mass/M = 56/56 = 1 mol.
Q130.Isotopes are atoms with same:
- A.same neutrons
- B.same A and Z
- C.atomic number but different mass number
- D.mass number but different Z
Show answer
Correct answer: C. atomic number but different mass number
Isotopes: same Z, different A.
Q131.Electronegativity order: F, O, N, C is:
- A.N > O > C > F
- B.F > O > N > C
- C.C > N > O > F
- D.O > F > N > C
Show answer
Correct answer: B. F > O > N > C
Electronegativity: F > O > N > C.
Q132.Colour of anhydrous copper sulfate (CuSO₄) is:
- A.white
- B.blue
- C.green
- D.yellow
Show answer
Correct answer: A. white
Anhydrous CuSO₄ is white; turns blue on absorbing water.
Q133.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.
Q134.Molar mass of C₂H₄ is:
- A.24 g/mol
- B.30 g/mol
- C.28 g/mol
- D.26 g/mol
Show answer
Correct answer: C. 28 g/mol
Add atomic masses: molar mass of C₂H₄ = 28 g/mol.
Q135.Oxidation state of nitrogen in N₂ gas is:
- A.+5
- B.0
- C.+3
- D.−3
Show answer
Correct answer: B. 0
Elemental N₂ has oxidation state 0.
Q136.Formula of copper(II) oxide is:
- A.CuO
- B.Cu₂O
- C.Cu₂O₃
- D.CuO₂
Show answer
Correct answer: A. CuO
Cu(+2) and O(−2): CuO.
Q137.When excess CO₂ is passed through Ca(OH)₂, precipitate:
- A.remains unchanged
- B.turns yellow
- C.turns red
- D.dissolves (Ca(HCO₃)₂ forms)
Show answer
Correct answer: D. dissolves (Ca(HCO₃)₂ forms)
CaCO₃ + CO₂ + H₂O → Ca(HCO₃)₂ (soluble).
Q138.Acid that cannot be stored in glass bottles is:
- A.H₂SO₄
- B.HNO₃
- C.HF
- D.HCl
Show answer
Correct answer: C. HF
HF etches glass (SiO₂ + 4HF → SiF₄ + 2H₂O).
Q139.Product of fermentation of glucose is:
- A.methanol and CO
- B.ethanol and CO₂
- C.acetic acid and H₂
- D.lactic acid
Show answer
Correct answer: B. ethanol and CO₂
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (yeast).
Q140.Halogens belong to which group?
- A.Group 17
- B.Group 1
- C.Group 16
- D.Group 18
Show answer
Correct answer: A. Group 17
Halogens are Group 17 elements.
Q141.Number of moles in 32 g of CH₄ (M = 16 g/mol) is:
- A.3
- B.1
- C.3.5
- D.2
Show answer
Correct answer: D. 2
n = mass/M = 32/16 = 2 mol.
Q142.Shape of s-orbital is:
- A.clover-leaf
- B.linear
- C.spherical
- D.dumbbell
Show answer
Correct answer: C. spherical
s-orbital is spherically symmetric.
Q143.Bond order in O₂ is:
- A.1.5
- B.2
- C.1
- D.3
Show answer
Correct answer: B. 2
O=O double bond; bond order = 2.
Q144.Laughing gas is:
- A.N₂O
- B.NO
- C.NO₂
- D.N₂
Show answer
Correct answer: A. N₂O
Laughing gas = nitrous oxide (N₂O).
Q145.If [H⁺] = 10⁻13 mol/L, the pH of the solution is:
- A.14
- B.1
- C.12
- D.13
Show answer
Correct answer: D. 13
pH = −log[H⁺] = −log(10⁻13) = 13.
Q146.Molar mass of C₂H₆ is:
- A.26 g/mol
- B.32 g/mol
- C.30 g/mol
- D.28 g/mol
Show answer
Correct answer: C. 30 g/mol
Add atomic masses: molar mass of C₂H₆ = 30 g/mol.
Q147.Oxidation state of copper in CuO is:
- A.+3
- B.+2
- C.+1
- D.0
Show answer
Correct answer: B. +2
O=−2, so Cu=+2.
Q148.Formula of magnesium nitrate is:
- A.Mg(NO₃)₂
- B.MgNO₃
- C.Mg₂NO₃
- D.Mg(NO₂)₂
Show answer
Correct answer: A. Mg(NO₃)₂
Mg(+2) and NO₃⁻: need 2 NO₃⁻.
Q149.Reaction of K with water produces:
- A.K₂O and H₂O
- B.K₂O₂ and H₂
- C.KH and O₂
- D.KOH and H₂
Show answer
Correct answer: D. KOH and H₂
2K + 2H₂O → 2KOH + H₂↑.
Q150.Common name of Ca(OH)₂ is:
- A.limestone
- B.marble
- C.slaked lime
- D.quicklime
Show answer
Correct answer: C. slaked lime
Ca(OH)₂ = slaked lime.
Q151.Reaction of carboxylic acid + alcohol (acid catalyst) gives:
- A.alkene
- B.ester
- C.ether
- D.aldehyde
Show answer
Correct answer: B. ester
RCOOH + R’OH ⇌ RCOOR’ + H₂O (esterification).
Q152.Lanthanides and actinides belong to:
- A.f-block
- B.d-block
- C.p-block
- D.s-block
Show answer
Correct answer: A. f-block
f-block elements have partly-filled f orbitals.
Q153.Number of moles in 192 g of SO₂ (M = 64 g/mol) is:
- A.4
- B.2
- C.4.5
- D.3
Show answer
Correct answer: D. 3
n = mass/M = 192/64 = 3 mol.
Q154.Aufbau principle: electrons fill orbitals in order of:
- A.random order
- B.n only
- C.increasing energy
- D.decreasing energy
Show answer
Correct answer: C. increasing energy
Electrons fill lowest-energy orbitals first.
Q155.Which molecule is polar?
- A.CO₂
- B.HCl
- C.Cl₂
- D.N₂
Show answer
Correct answer: B. HCl
HCl has a net dipole moment → polar.
Q156.Aqua regia is a mixture of:
- A.conc. HCl and conc. HNO₃ (3:1)
- B.conc. H₂SO₄ and HNO₃
- C.conc. HCl and H₂SO₄
- D.dilute HNO₃ and HCl
Show answer
Correct answer: A. conc. HCl and conc. HNO₃ (3:1)
Aqua regia = 3 parts HCl : 1 part HNO₃.
Q157.If [H⁺] = 10⁻1 mol/L, the pH of the solution is:
- A.2
- B.13
- C.3
- D.1
Show answer
Correct answer: D. 1
pH = −log[H⁺] = −log(10⁻1) = 1.
Q158.Molar mass of HNO₃ is:
- A.65 g/mol
- B.61 g/mol
- C.63 g/mol
- D.47 g/mol
Show answer
Correct answer: C. 63 g/mol
Add atomic masses: molar mass of HNO₃ = 63 g/mol.
Q159.Oxidation state of Cl in Cl₂ gas is:
- A.+7
- B.0
- C.−1
- D.+1
Show answer
Correct answer: B. 0
Elemental Cl₂: oxidation state 0.
Q160.Formula of sodium carbonate is:
- A.Na₂CO₃
- B.NaCO₃
- C.Na₂CO₂
- D.NaHCO₃
Show answer
Correct answer: A. Na₂CO₃
Na(+1) and CO₃²⁻: Na₂CO₃.
Q161.Gas produced when Cu reacts with conc. H₂SO₄ is:
- A.H₂
- B.CO₂
- C.SO₃
- D.SO₂
Show answer
Correct answer: D. SO₂
Cu + 2H₂SO₄(conc.) → CuSO₄ + SO₂ + 2H₂O.
Q162.Acid rain is caused mainly by:
- A.O₃ and Cl₂
- B.NH₃ and HF
- C.SO₂ and NO₂
- D.CO₂ and H₂O
Show answer
Correct answer: C. SO₂ and NO₂
SO₂ and NO₂ dissolve in rain → H₂SO₄ and HNO₃.
Q163.Product of dehydration of ethanol at 170°C is:
- A.acetaldehyde
- B.ethene
- C.ethane
- D.diethyl ether
Show answer
Correct answer: B. ethene
C₂H₅OH →(H₂SO₄, 170°C)→ CH₂=CH₂ + H₂O.
Q164.Element with symbol Au is:
- A.gold
- B.aluminium
- C.argentum (Ag)
- D.arsenic
Show answer
Correct answer: A. gold
Au from Latin ‘aurum’ (gold).
Q165.Number of moles in 184 g of NO₂ (M = 46 g/mol) is:
- A.5
- B.3
- C.5.5
- D.4
Show answer
Correct answer: D. 4
n = mass/M = 184/46 = 4 mol.
Q166.Hund’s rule: electrons occupy degenerate orbitals:
- A.randomly
- B.starting from highest energy
- C.one each before pairing
- D.in pairs first
Show answer
Correct answer: C. one each before pairing
Maximum spin multiplicity (Hund’s rule).
Q167.Hybridisation of carbon in ethyne (C₂H₂) is:
- A.dsp
- B.sp
- C.sp²
- D.sp³
Show answer
Correct answer: B. sp
C≡C triple bond; each C is sp hybridised.
Q168.Chemical formula of gypsum is:
- A.CaSO₄·2H₂O
- B.CaSO₄·½H₂O
- C.CaSO₄
- D.CaCO₃
Show answer
Correct answer: A. CaSO₄·2H₂O
Gypsum = calcium sulfate dihydrate.
Q169.If [H⁺] = 10⁻2 mol/L, the pH of the solution is:
- A.3
- B.12
- C.1
- D.2
Show answer
Correct answer: D. 2
pH = −log[H⁺] = −log(10⁻2) = 2.
Q170.Molar mass of AlCl₃ is:
- A.127 g/mol
- B.135 g/mol
- C.133.5 g/mol
- D.98 g/mol
Show answer
Correct answer: C. 133.5 g/mol
Add atomic masses: molar mass of AlCl₃ = 133.5 g/mol.
Q171.Oxidation state of hydrogen in NaH is:
- A.+2
- B.−1
- C.+1
- D.0
Show answer
Correct answer: B. −1
In metal hydrides, H is −1.
Q172.Formula of calcium phosphate is:
- A.Ca₃(PO₄)₂
- B.CaPO₄
- C.Ca₂PO₄
- D.Ca(PO₄)₂
Show answer
Correct answer: A. Ca₃(PO₄)₂
Ca(+2) and PO₄³⁻: Ca₃(PO₄)₂.
Q173.Lime water turns milky when CO₂ is passed because:
- A.Ca(OH)₂ dissolves
- B.CaO forms
- C.CO₂ reduces Ca(OH)₂
- D.CaCO₃ precipitates
Show answer
Correct answer: D. CaCO₃ precipitates
CO₂ + Ca(OH)₂ → CaCO₃↓ + H₂O.
Q174.Indicator that turns pink in base is:
- A.litmus
- B.starch
- C.phenolphthalein
- D.methyl orange
Show answer
Correct answer: C. phenolphthalein
Phenolphthalein: colourless in acid, pink in base.
Q175.Fehling’s solution gives brick-red precipitate with:
- A.esters
- B.aldehydes
- C.ketones
- D.carboxylic acids
Show answer
Correct answer: B. aldehydes
Aldehydes reduce Cu²⁺ to Cu₂O (brick-red).
Q176.Atomic number of nitrogen is:
- A.7
- B.14
- C.8
- D.6
Show answer
Correct answer: A. 7
N has 7 protons.
Q177.Number of moles in 500 g of CaCO₃ (M = 100 g/mol) is:
- A.6
- B.4
- C.6.5
- D.5
Show answer
Correct answer: D. 5
n = mass/M = 500/100 = 5 mol.
Q178.Pauli exclusion principle states:
- A.orbitals fill in order of energy
- B.each orbital holds one electron only
- C.no two electrons in an atom have same four quantum numbers
- D.electrons repel each other
Show answer
Correct answer: C. no two electrons in an atom have same four quantum numbers
Each electron has unique set of n, l, m, s.
Q179.Number of sigma bonds in ethane (C₂H₆) is:
- A.5
- B.7
- C.6
- D.8
Show answer
Correct answer: B. 7
C–C (1) + 6 C–H = 7 σ bonds.
Q180.Drying agent used in lab is:
- A.anhydrous CaCl₂
- B.NaCl
- C.KCl
- D.NH₄Cl
Show answer
Correct answer: A. anhydrous CaCl₂
Anhydrous CaCl₂ absorbs moisture (desiccant).