# Electric Field & Combination of Diverging and Converging Lenses Questions

The reason we can read print from any direction is that

1. the white part of a page reflects light in all directions.
2. letters emit black light in all directions.
3. letters absorb black light from all directions.

A resistor is something placed in a circuit that totally blocks the flow of electrons.

1. True
2. False

A 10 micro-Coulomb charge is located in a 400 N/C electric field. What is the force experienced by the charge?

a. b. c.

1 x 10-3. N
4 x 10-3. N
4 x 10-3. N/C

The electrical force on a 2 C charge is 20 N. What is the value of the electric field at the location of the charge?

1. 2N/C
2. 10 N/C
3. 20 N/C

Electrons move in an electric circuit

1. by being physically bumped by other electrons.
2. by interacting with an established electric field.
3. because the wires are so thin.

When light strikes the surface of a material like glass or water it is usually

1. completely reflected back from the surface of the material.
2. completely transmitted through the material.
3. partially transmitted and partially reflected.

Laser light is emitted when excited atoms of a solid, liquid, or gas are stimulated to emit photons in phase.

1. true
2. false

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An electroscope is charged positively, as shown by foil leaves that stand apart. As a negatively charged rod is brought close to the electroscope, the leaves

2. do not move.
3. move closer together.

If you stand 1 m in front of a plane mirror your image appears

1. less than 1 m behind the mirror.
2. 1 m behind the mirror.
3. more than 1 m behind the mirror.

Why does a farsighted person have trouble focusing on nearby objects?

1. images form in front of retina (eyeball is too long)
2. iris opening is too small
3. image forms behind retina (eyeball is too short)

Two charges separated a distance of 1.0 meter exert a 2.0-N force on each other. If the charges are pushed to a separation of meter, the force on each charge will be

1. 0.67 N.
2. 6.0 N.
3. 18.0 N.

Two charges separated by a distance of 1 meter exert a 20-N force on each other. If the charges are pulled to a 2 meter separation distance, the force on each charge will be

a. 5N. b. 10N. c. 40N.

Compared to gravity, the electromagnetic force is

2. much stronger.
3. much weaker.

What is the resistance of a toaster that uses 5 A of current when connected to a 120 volt power source? (Apply Ohm’s Law.)

1. 5 ohms
2. 24 ohms
3. 600 ohms

A magnifying glass is a

1. diverging lens.
2. combination of diverging and converging lenses.
3. converging lens.

When a wave slows down it

1. bends away from the normal.
2. bends toward the normal.
3. continues in a straight line. 