POST UTME BELLS UNIVERSITY 2019 Physics | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A 10 μCi source of 226 Ra decays by \alpha emission. What is the activity of the source after 2 half-lives?
A. 5 μCi
B. 2.5 μCi
C. 1.25 μCi
D. 0.625 μCi
Question 2
A 100 V AC source is connected to a 20 Ω resistor. What is the current flowing through the resistor?
A. 5 A
B. 10 A
C. 15 A
D. 20 A
Question 3
A 12 V battery is connected in series with a 4 Ω resistor and a 6 Ω resistor. What is the total resis\tance in the circuit?
A. 2 Ω
B. 4 Ω
C. 6 Ω
D. 10 Ω
Question 4
A parallel plate capacitor has a capaci\tance of 10 μF and is charged to a potential difference of 5 V. If a dielectric slab of thickness 2 mm and dielectric cons\tant 3 is inserted between the plates, what is the new capaci\tance?
A. 20 μF
B. 30 μF
C. 40 μF
D. 50 μF
Question 5
A radioactive sample decays at a rate of 0.5% per hour. If the initial mass of the sample is 100 g, what is the mass of the sample after 3 hours?
A. 90 g
B. 80 g
C. 70 g
D. 60 g
Question 6
A gas is enclosed in a container at a temperature of 300 K. If the temperature is increased to 400 K, what is the ratio of the final volume to the initial volume?
A. 1.33
B. 2.00
C. 3.00
D. 4.00
Question 7
A vector has a magnitude of 5 units and an angle of 30° with the positive x-axis. What is the x-component of the vector?
A. 4 units
B. 5 units
C. 6 units
D. 7 units
Question 8
A circuit consists of a 12 V battery, a 4 Ω resistor, and a 6 Ω resistor connected in series. What is the current flowing through the circuit?
A. 1 A
B. 2 A
C. 3 A
D. 4 A
Question 9
A sound wave with a frequency of 200 Hz is emitted from a source moving towards a stationary observer. If the speed of sound in air is 343 m/s, what is the apparent frequency heard by the observer?
A. 220 Hz
B. 200 Hz
C. 180 Hz
D. 160 Hz
Question 10
A radioactive sample decays from 100 g to 50 g in 10 minutes. What is the half-life of the sample?
A. 5 minutes
B. 10 minutes
C. 15 minutes
D. 20 minutes
Question 11
A 2 kg object is attached to a spring with a spring cons\tant of 100 N/m. What is the frequency of oscillation?
A. 0.5 Hz
B. 1 Hz
C. 2 Hz
D. 5 Hz
Question 12
A 1000 Hz AC voltage source is connected to a 50 Ω resistor in series with a 200 mH inductor. What is the phase angle between the voltage and current?
A. π/4
B. π/3
C. π/2
D. π/6
Question 13
A 100 W light bulb is connected to a 120 V AC source. What is the impedance of the bulb?
A. 50 Ω
B. 100 Ω
C. 150 Ω
D. 200 Ω
Question 14
A gas at 300 K has a volume of 2.5 L. If the temperature is increased to 400 K, what is the new volume of the gas?
A. 3.2 L
B. 3.5 L
C. 4.0 L
D. 4.5 L
Question 15
A particle of mass 2 kg is moving in a circular path of radius 3 m with a cons\tant speed of 4 m/s. If the particle is subjected to a centripetal acceleration of 2 m/s^2, what is the force acting on the particle?
A. 8 N
B. 10 N
C. 12 N
D. 16 N

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