Home Chapter 22 Practice Questions

# Practice Questions

This activity contains 21 questions.

## The above figure represents an electromagnetic wave frozen in time. The blue line is the

 frequency. wavelength. period.

## If the wavelength of the wave in the above question is 3 x 10-5m the wave is

 a radio wave. a microwave. an infrared wave. visible light wave. UV wave. X-ray.

## If the wavelength of the wave in Question 1 is 3 nm the wave is

 a radio wave. a microwave. an infrared wave. visible light wave. UV wave. X-ray.

## If the wavelength of the wave in Question 1 is 0.6 microns the wave is

 a radio wave. a microwave. an infrared wave. visible light wave. UV wave. X-ray.

## If the wavelength of the wave in Question 1 is 10 km the wave is

 a radio wave. a microwave. an infrared wave. visible light wave. UV wave. X-ray.

In the figure an electromagnetic wave is shown moving left to right. If the number in the upper right is the time measured in units of 100ps the wave is a

 a radio wave. a microwave. visible light wave. UV wave. X-ray.

## What is the wavelength of the wave in Question 6?

 1 cm. 1 meter. 4 meters. 15 meters. 1 km.

## If the time counter in Question 6 is clicking time in units of 0.2fs the wave is

 a radio wave. a microwave. an infrared wave. visible light wave. X-ray. None of the above

## The wavelength of the wave in Question 8 is

 10 m. 1.5 mm. .4 microns. 6 x 10-10 m.

## If the counter in Question 6 is counting in seconds the wave is

 a radio wave. a microwave. an infrared wave. UV wave. none of the above

## What would be the wavelength of the wave in Question 10?

 2000 m 10 km 2.5 x 104 km 3.0 x 106 km

If the electric vector in the E & M wave has a maximum value of 1000 V/m what is the value for the maximum of the magnetic vector?

 1.3 x 10 -6 T 2.3 x 10 -6 T 3.3 x 10 -6 T 4.3 x 10 -6 T

## What is the energy density (energy per cubic meter) in a small region of space in the above wave at an instant of time when the electric vector is a maximum?

 4.425 x 10-6 J/m3 8.85 x 10-9 J/m3 8.85 x 10-6 J/m3 1.77 x 10-6 J/m3

## What is the energy density (energy per cubic meter) carried by the magnetic field vector in a small region of space in the above wave at an instant of time when the electric vector is a maximum?

 1.77 x 10-5 J/m3 3 x 10 -6 J/m3 9 x 10 -9 J/m3 4.425 x 10-6 J/m3

## What is the average intensity of the E & M wave in Question 12 ?

 2655 W/m2 5310 W/m2 1328 W/m2 3 W/m2

## On a very clear day in summer the solar intensity in the 'little lattitudes' might reach 1000 W/m2 (averaged over time). What would be the maximum value for the electric vector?

 870 V/m 1750 V/m 750 V/m 250 V/m

## What is the (maximum) magnetic field vector in the above question?

 1 x 10 -6 T 2 x 10 -6 T 3 x 10 -6 T 4 x 10 -6 T

## As a capacitor charges

 there is an electric current through the capacitor. There is no electric current flowing in the circuit until the capacitor is fully charged. There is a displacement current between the plates of the capacitor.

## A 10 volt battery is connected to a switch, a 35 microF capacitor, and a 120 ohm resistor. Two milliseconds after the switch is closed, what is the voltage on the capacitor?

 1.2 V 2.8 V 3.8 V 10 V

## What is Maxwell's displacement current inside the capacitor in the previous question at 2 ms?

 16 mA 20 mA 57 mA 0 A

## What is the rate of change of the electric flux in the capacitor in Question 19?

 2 x 10 5 V/m3 2000 V/m3 2.7 x 10 20 V/m3 5.9 x 10 9 V/m3