Questions from Modern Physics

Q: You are analyzing an ac circuit that contains a solenoid and a

You are analyzing an ac circuit that contains a solenoid and a capacitor in series with an ac source that has voltage amplitude 90.0 V and angular frequency ω. For different capacitors in t...

Q: A satellite 575 km above the earth’s surface transmits sinusoidal electromagnetic waves

A satellite 575 km above the earth’s surface transmits sinusoidal electromagnetic waves of frequency 92.4 MHz uniformly in all directions, with a power of 25.0 kW. a. What is the intensity of these w...

Q: For a sinusoidal electromagnetic wave in vacuum, such as that described

For a sinusoidal electromagnetic wave in vacuum, such as that described by Eq. (32.16), show that the average energy density in the electric field is the same as that in the magnetic field.

Q: A coil has a resistance of 48.0 Ω. At

A coil has a resistance of 48.0 Ω. At a frequency of 80.0 Hz the voltage across the coil leads the current in it by 52.3°. Determine the inductance of the coil.

Q: What is the dc impedance of the electrode, assuming that it

What is the dc impedance of the electrode, assuming that it behaves as an ideal capacitor? a. 0; b. infinite; c. 2 * 104 Ω; d. 2 * 106 Ω.

Q: If the electrode oscillates between two points 20 µm apart at a

If the electrode oscillates between two points 20 µm apart at a frequency of (5000/π)Hz, what is the electrode’s impedance? a. 0; b. infinite; c. 2 * 104 Ω; d. 2 * 106 Ω.

Q: The signal from the oscillating electrode is fed into an amplifier,

The signal from the oscillating electrode is fed into an amplifier, which reports the measured voltage as an rms value, 1.5 nV. What is the potential difference between the two extremes? a. 1.5 nV;...

Q: If the frequency at which the electrode is oscillated is increased to

If the frequency at which the electrode is oscillated is increased to a very large value, the electrode’s impedance a. approaches infinity; b. approaches zero; c. approaches a constant but nonzero...

Q: Consider each of the electric- and magnetic-field orientations given

Consider each of the electric- and magnetic-field orientations given next. In each case, what is the direction of propagation of the wave? a. E in the +x-direction, B in the +y-direction; b. E in th...

Q: In an L-R-C series circuit, the components

In an L-R-C series circuit, the components have the following values: L = 20.0 mH, C = 140 nF, and R = 350 Ω. The generator has an rms voltage of 120 V and a frequency of 1.25 kHz. Determine a. the p...