Physics Exam 2

What happens to the current supplied by the battery when you add an identical bulb in parallel to the original bulb

The current doubles

A constant voltage is applied across a circuit. If the resistance in the circuit is doubled, what is the effect on the power dissipated by the circuit?

The power dissipated is reduced by a factor of 2.

In a series circuit with two identical bulbs, what happens to the remaining bulb when one is replaced with a wire

The remaining bulb gets brighter

How do the resistances of two conducting wires compare if they have the same length, but one is twice the radius of the other The thicker wire has half the resistance of the thinner wire. The resistance is the same in both wires. The thicker wire has twice the resistance of the thinner wire. The thicker wire has one-fourth the resistance of the thinner wire.

The thicker wire has one-fourth the resistance of the thinner wire.

At the same temperature, two wires made of pure copper have different resistances. The same voltage is applied at the ends of each wire. The wires may differ in

length cross-sectional area amount of electric current passing through them.

An ideal measuring device is one that does not alter the very measurement it is meant to take. Therefore, in comparison with the resistance being measured, the resistances of an ideal ammeter and an ideal voltmeter must be, respectively: very small; very small very large; very small very small; very large very large; very large

very small; very large

If you want to measure the voltage across and the current through a resistor, then the circles marked 1, 2 and 3, shown in the diagram, must represent, respectively: 1 = ammeter, 2 = resistor, 3 = voltmeter 1 = ammeter, 2 = voltmeter, 3 = resistor 1 = resistor, 2 = voltmeter, 3 = ammeter 1 = resistor, 2 = ammeter, 3 = voltmeter 1 = voltmeter, 2 = resistor, 3 = ammeter 1 = voltmeter, 2 = ammeter, 3 = resistor

1 = resistor, 2 = ammeter, 3 = voltmeter 1 = voltmeter, 2 = ammeter, 3 = resistor

Consider a wire that has resistance R, length L and the cross-sectional area A. The correct expression for the resistivity of that wire is AL/R A/RL AR/L R/LA

AR/L

The SI unit of electric current is equivalent to: second ⋅ Coulomb second / Coulomb second + Coulomb Coulomb / second

Coulomb / second

If the resistivity of copper is less than that of gold at room temperature, which of the following statements must be true? Electrons in gold are more likely to be scattered than electrons in copper at room temperature when they are accelerated by the same electric field. The sample of gold is thinner than the sample of copper. Gold has a higher resistance than copper. There is more current flowing in the gold than in the copper.

Electrons in gold are more likely to be scattered than electrons in copper at room temperature when they are accelerated by the same electric field.

Which of the following will increase the resistance of a wire? Increasing the length of the wire will increase the resistance of the wire. Increasing the cross-sectional area of the wire will increase the resistance of the wire. Decreasing the cross-sectional area of the wire will increase the resistance of the wire. Increasing the resistivity of the material the wire is composed of will increase the resistance of the wire. Decreasing the length of the wire will increase the resistance of the wire. Decreasing the resistivity of the material the wire is composed of will increase the resistance of the wire.

Increasing the length of the wire will increase the resistance of the wire. Decreasing the cross-sectional area of the wire will increase the resistance of the wire. Increasing the resistivity of the material the wire is composed of will increase the resistance of the wire.

The SI unit of voltage (aka "electric potential difference") is equivalent to: Newton ⋅ Coulomb Newton / Coulomb Joule ⋅ Coulomb Joule / Coulomb Watt ⋅ Coulomb Watt / Coulomb

Joule / Coulomb

If the voltage across a conductor is V, and the current through the conductor is I, the resistance of the conductor is defined as: R=VI R=I/V R=V/I

R=V/I

The junction rule describes the conservation of which quantity? Note that this rule applies only to circuits that are in a steady state

charge

Which of the following would double the amount of current flowing through a piece of metal wire? Halve the voltage across it Double the voltage across it Quarter the voltage across it Quadruple the voltage across it.

double the voltage across it