POST UTME UNN 2020 Physics | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A light ray passes from air into a glass slab of thickness 6 cm and re\fractive index 1.5. If the angle of incidence is 30°, calculate the angle of re\fraction.
A. 20°
B. 25°
C. 30°
D. 35°
Question 2
A 10 μF capacitor is connected in parallel with a 20 μF capacitor. If a 50 V battery is connected across the combination, what is the equivalent capaci\tance?
A. 10 μF
B. 20 μF
C. 30 μF
D. 40 μF
Question 3
A lens of focal length $f$ is placed in a beam of light. If the beam is parallel to the axis of the lens, determine the nature of the image formed by the lens.
A. real and inverted
B. virtual and upright
C. real and upright
D. virtual and inverted
Question 4
A light ray passes through a prism with an angle of incidence of 30° and an angle of re\fraction of 20°. If the prism has a re\fractive index of 1.5, calculate the angle of emergence.
A. 25°
B. 30°
C. 35°
D. 40°
Question 5
A 2.5 mH inductor is connected in series with a 10 V AC source. If the frequency of the source is 50 Hz, what is the inductive reac\tance of the circuit?
A. \( 2.5 \times 10^{-3} \times 2 pi \times 50 \) Ω
B. \( 2.5 \times 10^{-3} \times 2 pi \times 100 \) Ω
C. \( 2.5 \times 10^{-3} \times 2 pi \times 150 \) Ω
D. \( 2.5 \times 10^{-3} \times 2 pi \times 200 \) Ω
Question 6
A 5 kg body is moving with a velocity of 10 m/s. If the body is subjected to a force of 20 N, what is the acceleration of the body?
A. \( \frac{20}{5} \) m/s^2
B. \( \frac{20}{10} \) m/s^2
C. \( \frac{20}{15} \) m/s^2
D. \( \frac{20}{20} \) m/s^2
Question 7
A magnetic field of 0.5 T is applied to a coil of 100 turns and area 0.01 m^2. Calculate the torque experienced by the coil.
A. 0.1 Nm
B. 0.2 Nm
C. 0.3 Nm
D. 0.4 Nm
Question 8
A 5 kg block is attached to a horizontal spring with a force cons\tant of 100 N/m. If the block is displaced by 2 m from its equilibrium position and released, what is the maximum speed of the block?
A. 2 m/s
B. 4 m/s
C. 6 m/s
D. 8 m/s
Question 9
A radioactive sample of Δₗ emits Δₗ particles at a rate of 1.5 ± 0.1 decays per minute. If the half-life of Δₗ is 5.27 ± 0.02 minutes, what is the mean lifetime of the sample?
A. ( 3.45 pm 0.23 ) minutes
B. ( 6.54 pm 0.41 ) minutes
C. ( 9.63 pm 0.59 ) minutes
D. ( 12.72 pm 0.77 ) minutes
Question 10
A block of mass $M$ is placed on a horizontal surface with a coefficient of static friction $\mu_s$. If a force $F$ is applied to the block, determine the maximum value of $F$ for which the block will remain at rest.
A. \mu_sMg
B. \frac{\mu_sMg}{2}
C. \frac{Mg}{\mu_s}
D. \frac{2\mu_sMg}{3}
Question 11
A 10 Ω resistor is connected to a 20 Ω resistor in parallel. What is the equivalent resis\tance?
A. 5 Ω
B. 10 Ω
C. 15 Ω
D. 20 Ω
Question 12
A particle of mass 2 kg is attached to a spring with a spring cons\tant of 100 N/m. It is displaced by 0.2 m from its equilibrium position and released from rest. Assuming the motion is simple harmonic, calculate the total energy of the particle at time t = 0.
A. 10 J
B. 20 J
C. 30 J
D. 40 J
Question 13
A quantum particle of mass $m$ is confined to a one-dimensional box of length $L$. If the particle is in the ground state, determine the expectation value of its position.
A. 0
B. \frac{L}{2}
C. L
D. \frac{L}{4}
Question 14
A gas is heated from 20°C to 50°C. If the initial volume is 2 L, what is the final volume?
A. 4 L
B. 6 L
C. 8 L
D. 10 L
Question 15
A particle of mass $m$ is attached to a spring with spring cons\tant $k$. If the particle is displaced by a dis\tance $x$ from its equilibrium position and released from rest, determine the angular frequency of the resulting simple harmonic motion.
A. \sqrt{\frac{k}{m}}
B. \frac{k}{m}
C. \frac{m}{k}
D. \frac{1}{\sqrt{mk}}

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Help others prepare! Share this practice hub: