POST UTME KSU 2021 Physics | Objective

Are you preparing for POST UTME KSU exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2021 Physics (Objective) questions designed to simulate the real exam environment.

Practice these randomly selected questions to test your readiness.

Question 1
A radioactive sample emits \alpha particles with a half-life of 4.5 years. If the initial activity is 100 Bq, what is the activity after 18 years?
Correct A. 12.5 Bq
B. 25 Bq
C. 50 Bq
D. 100 Bq

Correct Answer: A

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Question 2
A 2.5 V battery is connected in series with a 10 Ω resistor and a 20 Ω resistor. What is the current flowing through the circuit?
A. 0.25 A
Correct B. 0.5 A
C. 1 A
D. 2 A

Correct Answer: B

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Question 3
A lens with a focal length of 20 cm is used to form an image of an object 30 cm away. What is the magnification of the image?
Correct A. 0.5
B. 1
C. 2
D. 3

Correct Answer: A

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Question 4
A particle of mass 2 kg is moving in a circular path with a radius of 5 m. If the particle has a speed of 10 m/s, what is the centripetal force acting on it?
A. 20 N
Correct B. 40 N
C. 60 N
D. 80 N

Correct Answer: B

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Question 5
A light ray passes through a prism with an angle of incidence of 30° and an angle of re\fraction of 20°. What is the angle of deviation?
A. 10°
B. 20°
Correct C. 30°
D. 40°

Correct Answer: C

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Question 6
A light ray passes from air into a glass slab of thickness 2.5 cm and re\fractive index 1.5. If the angle of incidence is 30°, find the angle of re\fraction.
A. 20°
Correct B. 25°
C. 30°
D. 35°

Correct Answer: B

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Question 7
A radioactive sample has a half-life of 5 years. If the initial activity is 100 Bq, find the activity after 10 years.
Correct A. 12.5 Bq
B. 25 Bq
C. 50 Bq
D. 100 Bq

Correct Answer: A

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Question 8
A charged particle moves in a magnetic field of strength 0.5 T. If the particle has a charge of 2 × 10^-19 C and a velocity of 3 × 10^6 m/s, find the force experienced by the particle.
A. 1.5 × 10^-14 N
Correct B. 3 × 10^-14 N
C. 4.5 × 10^-14 N
D. 6 × 10^-14 N

Correct Answer: B

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Question 9
A projectile is launched at an angle of 60° to the horizontal with an initial velocity of 20 m/s. If the acceleration due to gravity is 9.8 m/s^2, find the maximum height reached by the projectile.
A. 10 m
Correct B. 15 m
C. 20 m
D. 25 m

Correct Answer: B

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Question 10
A vector has a magnitude of 5 units and makes an angle of 30° with the x-axis. Find the x and y components of the vector.
Correct A. A_x = 4, A_y = 2.5
B. A_x = 3, A_y = 4
C. A_x = 2, A_y = 4.5
D. A_x = 1, A_y = 4.8

Correct Answer: A

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Question 11
A 2 kg block of metal is heated from 20°C to 80°C. If the specific heat capacity of the metal is 0.5 kJ/kg°C, calculate the heat energy transferred to the block.
A. 400 J
B. 800 J
Correct C. 1200 J
D. 1600 J

Correct Answer: C

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Question 12
A 10 Ω resistor is connected in series with a 20 Ω resistor and a 30 Ω resistor. If a 12 V battery is connected across the circuit, what is the total resis\tance of the circuit?
A. 60 Ω
B. 80 Ω
Correct C. 100 Ω
D. 120 Ω

Correct Answer: C

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Question 13
A magnetic field of 0.5 T is applied to a coil of wire with 100 turns. If the coil has a radius of 0.1 m, what is the magnetic flux through the coil?
A. 0.05 Wb
Correct B. 0.1 Wb
C. 0.15 Wb
D. 0.2 Wb

Correct Answer: B

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Question 14
A projectile is launched from the ground with an initial velocity of 20 m/s at an angle of 30° above the horizontal. If the acceleration due to gravity is 9.8 m/s², what is the maximum height reached by the projectile?
A. 10 m
B. 15 m
Correct C. 20 m
D. 25 m

Correct Answer: C

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Question 15
A capacitor of 100 μF is connected in series with a resistor of 10 kΩ. If a 12 V battery is connected across the circuit, what is the time cons\tant of the circuit?
A. 0.1 s
B. 0.5 s
Correct C. 1 s
D. 2 s

Correct Answer: C

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Question 16
A 2.5 m long wire of resis\tance 5 Ω is connected in series with a 10 V battery. If the wire is stretched to 3.5 m, what is the new resis\tance?
A. 7.5 Ω
B. 10 Ω
Correct C. 12.5 Ω
D. 15 Ω

Correct Answer: C

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Question 17
A body of mass 5 kg is moving in a circular path of radius 2 m with a cons\tant speed of 4 m/s. What is the magnitude of the force acting on the body?
A. 10 N
Correct B. 20 N
C. 30 N
D. 40 N

Correct Answer: B

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Question 18
A ray of light passes through a prism and is re\fracted at an angle of 30°. If the angle of incidence is 20°, what is the angle of emergence?
A. 10°
B. 20°
Correct C. 30°
D. 40°

Correct Answer: C

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Question 19
A heat engine operates between the temperatures 300 K and 500 K. If the efficiency of the engine is 30%, what is the work done per cycle?
A. 100 J
B. 200 J
Correct C. 300 J
D. 400 J

Correct Answer: C

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Question 20
A particle of mass 2 kg is moving in a straight line with an initial velocity of 5 m/s. If the particle experiences a cons\tant acceleration of 2 m/s², what is the velocity after 3 seconds?
A. 7 m/s
B. 8 m/s
Correct C. 9 m/s
D. 10 m/s

Correct Answer: C

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Question 21
A block of mass 5 kg is susp\ended from a spring with a spring cons\tant of 200 N/m. If the block is displaced by 0.2 m from its equilibrium position and released, what is the maximum speed of the block?
A. 2 m/s
B. 4 m/s
Correct C. 6 m/s
D. 8 m/s

Correct Answer: C

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Question 22
A parallel plate capacitor has a capaci\tance of 10 μF. If a voltage of 20 V is applied across it, what is the energy stored in the capacitor?
A. 0.2 J
Correct B. 0.4 J
C. 0.6 J
D. 0.8 J

Correct Answer: B

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Question 23
A current of 5 A flows through a resistor of 10 Ω. What is the power dissipated by the resistor?
A. 25 W
Correct B. 50 W
C. 75 W
D. 100 W

Correct Answer: B

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Question 24
A gas is heated from 300 K to 400 K. What is the ratio of the final volume to the initial volume?
A. 1.33
B. 1.5
Correct C. 1.67
D. 2

Correct Answer: C

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Question 25
A magnetic field of 0.5 T is applied to a coil of 100 turns. If the coil is rotated by 90°, what is the induced emf?
A. 0.5 V
Correct B. 1 V
C. 2 V
D. 5 V

Correct Answer: B

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