Physics Answers

Is polarization a property of all electromagnetic waves, or is it unique to visible light? Can

sound waves be polarized? What fundamental distinction in wave properties is involved?

Explain.

An inductor, a capacitor, and a resistor are all connected in series across an ac source.

If the resistance, inductance, and capacitance are all doubled, by what factor does each of the following quantities change? Indicate whether they increase or decrease: (a) the resonance angular frequency; (b) the inductive reactance; (c) the capacitive reactance. (d) Does the impedance double?

A hair dryer is treated as a pure resistor. But because there are coils in the heating element and in the motor that drives the blower fan, a hair dryer also has inductance.

Qualitatively, does including an inductance increase or decrease the values of R, Irms, and P?

In an R-C circuit, a resistor, an uncharged capacitor, a dc battery, and an open switch are

in series. In an R-L circuit, a resistor, an inductor, a dc battery, and an open switch are in series. Compare the behavior of the current in these circuits (a) just after the switch is closed and (b) long after the switch has been closed. In other words, compare the way in which a capacitor and an inductor affect a circuit.

Two closely wound circular coils have the same number of turns, but one has twice the

radius of the other. How are the self-inductances of the two coils related? Explain your

reasoning.

A KTM commuter train travels between two stations, A and B. The train starts from rest from station A and accelerates at a constant rate for 0.5 km until it reaches a speed of 30 m/s. It then travels at this constant speed for T s before decelerating at a constant rate of 1.5 m/s² and coming to rest at station B. Figure 1 shows the velocity-time graph of the train’s journey between the two stations. Determine the value of T if the distance between the two stations 6 km. Calculate also the total time taken for the whole journey.

A car is speeding up and has an instantaneous velocity of 1.0 m/s in the +x-direction when a stopwatch reads 10.0 s. It has a constant acceleration of 2.0 m/s² in the x-direction. (a) What change in speed occurs between t = 10.0 s and t = 12.0 s? (b) What is the speed when the stopwatch reads 12.0 s?

A car is speeding up and has an instantaneous velocity of 1.0 m/s in the +x-direction when a stopwatch reads 10.0 s. It has a constant acceleration of 2.0 m/s² in the x-direction. (a) What change in speed occurs between t = 10.0 s and t = 12.0 s? (b) What is the speed when the stopwatch reads 12.0 s?

A car is speeding up and has an instantaneous velocity of 1.0 m/s in the +x-direction when a stopwatch reads 10.0 s. It has a constant acceleration of 2.0 m/s² in the x-direction. (a) What change in speed occurs between t = 10.0 s and t = 12.0 s? (b) What is the speed when the stopwatch reads 12.0 s?

A car is speeding up and has an instantaneous velocity of 1.0 m/s in the +x-direction when a stopwatch reads 10.0 s. It has a constant acceleration of 2.0 m/s² in the x-direction. (a) What change in speed occurs between t = 10.0 s and t = 12.0 s? (b) What is the speed when the stopwatch reads 12.0 s?