|
1 | The electromotive force is a force exerted on an electric charge to keep it moving. |
| A) | True |
| B) | False |
|
2 | The direction of conventional current for a conductor is opposite to the direction of electron flow. |
| A) | True |
| B) | False |
|
3 | Electric current is also a measure of the average speed with which electrons move in a conductor. |
| A) | True |
| B) | False |
|
4 | According to Ohm’s law, the electric current is inversely proportional to the applied voltage. |
| A) | True |
| B) | False |
|
5 | Electric resistance increases with an increase in the cross-sectional area of a conductor. |
| A) | True |
| B) | False |
|
6 | The resistivity of a wire is independent of the length of the wire. |
| A) | True |
| B) | False |
|
7 | A wire with a diameter of 0.002 in. has a cross-sectional area of 4 cmils. |
| A) | True |
| B) | False |
|
8 | The temperature coefficient of resistance is equal to the change in resistance per degree change in temperature. |
| A) | True |
| B) | False |
|
9 | The power loss in a wire is quadrupled if the current is doubled. |
| A) | True |
| B) | False |
|
10 | A rheostat is a meter that indicates the electric resistance in a circuit. |
| A) | True |
| B) | False |
|
11 | A unit of electromotive force is the |
| A) | joule |
| B) | newton |
| C) | volt |
| D) | watt |
|
12 | If one were to use a water analogy to study electric current, voltage would be most similar to |
| A) | force |
| B) | pressure |
| C) | rate of flow |
| D) | density |
|
13 | The resistance of a wire is not dependent on its |
| A) | temperature |
| B) | length |
| C) | area |
| D) | current |
|
14 | Which of the following is not a measure of electric power? |
| A) | VR² |
| B) | VI |
| C) | I²R |
| D) | V²/R |
|
15 | Which of the following is not a unit resistivity? |
| A) | Ω * cm |
| B) | Ω * cmil/ft |
| C) | Ω/ft |
| D) | Ω * m |
|
16 | The potential difference between the terminals of a small heater is 60 V. If the resistance of the heater is 30 Ω, the current is |
| A) | 0.5 A |
| B) | 2 A |
| C) | 1800 A |
| D) | 3 A |
|
17 | An emf of 12 V will move 6.25 X 1018 electrons past a given point in 2 s. The resistance is |
| A) | 24 Ω |
| B) | 121 Ω |
| C) | 6 Ω |
| D) | 3.84 Ω |
|
18 | A 120-V heater has a resistance of 600 Ω. The heat energy generated in 1 min is |
| A) | 24 J |
| B) | 120 J |
| C) | 1200 J |
| D) | 1440 J |
|
19 | An aluminum wire has a resistivity of 17 Ω*cmils/ft and a cross-sectional diameter of 0.2 in. What length of this wire is needed to construct a 1700-Ω resistor? |
| A) | 200 ft |
| B) | 144.5 ft |
| C) | 4 X 106 ft |
| D) | 2 X 104 ft |
|
20 | The temperature coefficient of resistance for copper is 0.004/C°. If the resistance of a copper wire is 12 Ω at 20°C, its resistance at 100°C will be |
| A) | 3.8 Ω |
| B) | 13 Ω |
| C) | 15.84 Ω |
| D) | 50.4 Ω |
|
21 | A source of emf of one will perform one of on each coulomb of
charge that passes through it. |
|
22 | The current in a resistor is directly proportional to the and inversely proportional to the . This is a statement of . |
|
23 | Four factors that affect the resistance of a wire are , , , and . |
|
24 | The temperature coefficient of resistance is the change in per unit per unit change in . |
|
25 | The rate of heat loss in a wire can be found from the product of the and the square of the . |
|
26 | The direction of conventional current is always the same as the direction in which would move. |
|
27 | The area of a wire in equals the square of the in mils. |
|
28 | The resistance of a conductor at a given temperature is directly proportional to its , inversely proportional to its , and dependent on a material constant called its . |
|
29 | Three laboratory devices used to study resistance, current, and voltage are , , and respectively. |
|
30 | A source of electromotive force can convert energy to energy. |