Post Utme Physics Past Questions and Answers

Question 1151:

A car is stopped for a traffic signal. When the light turns green, the car accelerates, increasing its speed from 0 to \(5.20 m / s\) in \(0.832 s\). What is the average total force experienced by a \(70 kg\) passenger in the car during the time the car accelerates?

A. \(364 N\)
B. \(43.5 N\)
C. \(437.5 N\)
D. \(4375 N\)

Question 1152:

A parallel - plate capacitor filled with air carries a charge \(Q\). The battery is disconnected, and a slap of material with dielectric constant \(k=2\) is inserted between the plates. Which of the following statements is true?

A. The voltage across the capacitor decreases by a factor of 2
B. The voltage across the capacitor is doubled
C. The charge on the plate is doubled.
D. The charge on the plate decreases by a factor of 2

Question 1153:

A small object of mass \(3.80 g\) and charge \(-18 \mu C\) is
suspended motionless above the ground, when im. mersed in a uniform electric field perpendicular to the ground. What is the magnitude of the electric field?
\(\left[g=10 m / s ^{2}\right]\)

A. \(2.1 \times 10^{3} N / C\)
B. \(2.1 \times 10^{2} N / C\)
C. \(1.8 N / C\)
D. \(1.8 \times 10^{2} N / C\)

Question 1154:

When connected to a 120- \(V\) source, an electric heater is rated at \(1200 W\) and a toaster at \(600 W\). If both appliances are operating in parallel on a \(120-V\) circuit, what total current is delivered by an external source?

A. \(12 A\)
B. \(24 A\)
C. \(15 A\)
D. \(8 A\)

Question 1155:

Which of the following actions will increase the speed of sound in air?

A. Decreasing the air temperature
B. Increasing the frequency of the sound
C. Increasing the temperature
D. Reducing the pressure of the air