POST UTME REDEEMERS UNIVERSITY 2022 Physics | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 1000 Hz AC voltage source is connected to a 50 Ω resistor. If the maximum voltage is 100 V, calculate the root mean square (RMS) value of the current flowing through the resistor.
A. 2.83 A
B. 5.66 A
C. 8.49 A
D. 11.32 A
Question 2
A block of mass $m$ is attached to a horizontal, massless spring with a spring cons\tant $k$. The block is displaced by a dis\tance $x$ from its equilibrium position and released from rest. Assuming the block undergoes simple harmonic motion, what is the kinetic energy of the block at time $t$?
A. $K = \frac{1}{2}momega^2x^2\sin^2(omega t)$
B. $K = \frac{1}{2}momega^2x^2\cos^2(omega t)$
C. $K = \frac{1}{2}momega^2x^2\sin(omega t)$
D. $K = \frac{1}{2}momega^2x^2\cos(omega t)$
Question 3
A block of mass 5 kg is placed on a horizontal surface with a coefficient of kinetic friction of 0.2. If the block is pulled with a force of 20 N, calculate the acceleration of the block.
A. 0.40 m/s^2
B. 0.80 m/s^2
C. 1.20 m/s^2
D. 1.60 m/s^2
Question 4
A parallel plate capacitor has a capaci\tance of 10 μF and is charged to a potential difference of 12 V. If the plates are separated by a dis\tance of 2 mm, what is the surface charge density on the plates?
A. 1.2 x 10^\( -4 \) C/m^2
B. 2.4 x 10^\( -4 \) C/m^2
C. 3.6 x 10^\( -4 \) C/m^2
D. 4.8 x 10^\( -4 \) C/m^2
Question 5
A light ray passes from air into a glass slab of re\fractive index 1.5. If the angle of incidence is 30°, what is the angle of re\fraction?
A. 20°
B. 25°
C. 30°
D. 35°
Question 6
A coil of wire is placed in a magnetic field with a magnetic flux density of 0.5 T. If the coil has 100 turns and a cross-sectional area of 0.01 m^2, what is the induced emf in the coil?
A. 0.25 V
B. 0.5 V
C. 1 V
D. 2 V
Question 7
A gas is compressed from an initial volume of 2 L to a final volume of 1 L at a cons\tant temperature of 300 K. What is the work done on the gas?
A. 200 J
B. 400 J
C. 600 J
D. 800 J
Question 8
A radioactive sample emits \alpha particles with a half-life of 5 days. If the initial activity is 1000 Bq, calculate the activity after 10 days.
A. 125 Bq
B. 250 Bq
C. 500 Bq
D. 1000 Bq
Question 9
A current of 5 A flows through a resistor of 10 Ω for 2 seconds. What is the energy dissipated in the resistor?
A. 50 J
B. 100 J
C. 150 J
D. 200 J
Question 10
A circuit consists of a 10 Ω resistor, a 20 Ω resistor, and a 5 Ω resistor connected in series. What is the equivalent resis\tance of the circuit?
A. 35 Ω
B. 40 Ω
C. 45 Ω
D. 50 Ω
Question 11
A circuit consists of a 10 Ω resistor, a 20 Ω resistor, and a 30 Ω resistor connected in series. If a voltage of 12 V is applied across the circuit, calculate the current flowing through the 20 Ω resistor.
A. 0.4 A
B. 0.6 A
C. 0.8 A
D. 1.0 A
Question 12
A particle of mass $m$ is projected from the origin with an initial velocity $v_0$ at an angle $\theta$ to the horizontal. If the particle experiences a uniform downward acceleration $g$, what is the time of flight?
A. $\frac{2v_0 \sin \theta}{g}$
B. $\frac{v_0 \sin \theta}{g}$
C. $\frac{v_0 \cos \theta}{g}$
D. $\frac{v_0 \sin \theta}{g} \sin \theta
Question 13
A thermodynamic system undergoes a process from state A to state B, where the initial temperature is 300 K and the final temperature is 400 K. If the heat capacity at cons\tant volume is 20 J/K and the heat capacity at cons\tant pressure is 30 J/K, calculate the change in internal energy (ΔU) and the change in enthalpy (ΔH) for the process.
A. -1000 J
B. 1000 J
C. -2000 J
D. 2000 J
Question 14
A 10 μF capacitor is connected in series with a 20 Ω resistor and a 5 V battery. What is the current flowing through the circuit?
A. 0.25 A
B. 0.5 A
C. 0.75 A
D. 1 A
Question 15
A car travels from point A to point B with an average speed of 40 km/h. If the dis\tance between points A and B is 80 km, what is the time taken for the journey?
A. 2 h
B. 2.5 h
C. 3 h
D. 3.5 h

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: