Liberty University - PHYS 101

Quiz 7

Question1)An iron nail is brought near a magnet. Which of these is not true?

Question 2

An atom with fewer electrons than protons is

Question 3

Why do we use fuses?

• Question 4

Suppose current is flowing in a wire from right to left. Which way do the electrons in the wire move?

• Question 5

A heater is rated at 1200 watts for a 120-volt source.

If two heaters are connected in parallel across the 120-volt source, the current in amperes drawn from the source is

.

• Question 6

An object at an initial temperature of 27 ^oC is raised to a temperature of 877 ^oC. How much more energy does the object emit as blackbody radiation at the higher temperature compared to the lower temperature?

• Question 7

Two charged bodies separated by a distance d exert an electrical force on each other. The distance d is doubled. The electrical force on each body now

• Question 8

The type of EM radiation that has wavelength just a bit longer than that of visible light is

• Question 9

If I short out a D cell and draw a current of 7 A for 5 s, how many coulombs of charge move through the circuit?

• Question 10

The main form of radiation that our bodies emit is

• Question 11

A light bulb used in a slide projector draws a current of 6 amperes when operating on 120 volts.

If two slide projectors are connected in series across the same 120-volt source, the current drawn from the source in amperes is

.

• Question 12

The electric field shown is produced by a single point charge at the center of the picture.

If a new positive point charge is placed at location A directly to the right of the one pictured, the force on it will

• Question 13

A magnetic field exerts a force on an electric charge if the charge is

Question 14

About how hot does something have to get to glow red hot?

• Question 15

The EM wave that has the lowest frequency in this list is

• Question 16

For a body emitting blackbody radiation, the total power emitted is proportional to the 4th power of the body’s absolute temperature:

(T in kelvins)

and the wavelength of the emitted EM radiation that has the highest intensity is inversely proportional to the body’s absolute temperature according to:

(         in meters, T in kelvins)

Assume an object is emitting blackbody radiation.

The peak of a body’s blackbody radiation curve shifts upward as the temperature of the body increases.

• Question 17

Current is the rate of flow of electric charge.

• Question 18

An atom with fewer electrons than protons is a negative ion.

• Question 19

For a body emitting blackbody radiation, the total power emitted is proportional to the 4th power of the body’s absolute temperature:

(T in kelvins)

and the wavelength of the emitted EM radiation that has the highest intensity is inversely proportional to the body’s absolute temperature according to:

(         in meters, T in kelvins)

Assume an object is emitting blackbody radiation.

As the temperature of a body increases the color of the body shifts from blue to red.

Question 20

A light bulb used in a slide projector draws a current of 6 amperes when operating on 120 volts.

If two slide projectors are connected in parallel across the same 120-volt source, the current drawn from the source remains at 6 amperes.

• Question 21

A heater is rated at 1200 watts for a 120-volt source.

If two heaters are connected in parallel across the 120-volt source, the current drawn from the source is 10 amperes.

• Question 22

The greenhouse effect occurs because carbon dioxide in the atmosphere absorbs ultraviolet radiation.

• Question 23

A stationary electric charge produces a magnetic field around it.