Electricity Quiz
Questions: 16 · 10 minutes
1. A student wants to measure the current through a lamp. How should the ammeter be connected?
In parallel with the lamp so it measures the potential difference
In series with the lamp so the same current passes through both
Across the battery without any other component
Beside the circuit without making electrical contact
2. An ideal transformer has half as many turns on its secondary coil as on its primary coil. If the primary receives 230 volts AC, what secondary voltage is expected?
460 volts AC
230 volts AC
57.5 volts AC
115 volts AC
3. How should a voltmeter be connected to measure the voltage across a resistor?
In series before the resistor
In parallel across the resistor
In place of the power source
Between two points on the same uninterrupted wire
4. One lamp is connected to an ideal battery. A second identical lamp is then added in parallel. How does the first lamp's brightness compare with before?
It becomes much dimmer because the current is shared equally
It stays approximately the same because it still receives the full battery voltage
It doubles because the total circuit current increases
It goes out because parallel branches block current
5. Which unit is used to measure electrical resistance?
Farad
Tesla
Ohm
Henry
6. An electric kettle operates at 230 volts and draws 10 amperes. What electrical power does it use?
0.043 watts
230 watts
23 watts
2,300 watts
7. Which statement best defines electric current?
The energy transferred by a circuit each second
The electric potential energy stored in a component
The opposition a material gives to moving charge
The rate at which electric charge passes a point
8. A 4-ohm resistor has 12 volts across it. According to Ohm's law, what current flows through it?
0.33 amperes
2 amperes
48 amperes
3 amperes
9. What does a voltage of one volt represent?
One coulomb of charge passing each second
One joule of energy transferred each second
One joule of energy transferred per coulomb of charge
One ampere of current opposed by one watt
10. What is the intended function of a correctly rated fuse in a circuit?
To keep the supply voltage exactly constant
To melt and break the circuit when current becomes excessive
To store excess electrical energy for later use
To increase resistance during normal operation
11. What is the SI unit of electric charge?
Volt
Ampere
Coulomb
Watt
12. A low-resistance wire accidentally connects the two terminals of a battery directly. What is the main electrical concern?
A very large current may flow and cause dangerous heating
The wire prevents any charge from moving
The battery voltage immediately becomes alternating voltage
The battery stores extra charge without releasing energy
13. A 2-ohm resistor and a 3-ohm resistor are connected in series. What is their combined resistance?
0.83 ohms
1.5 ohms
5 ohms
2.5 ohms
14. A battery and two lamps form one series loop. What happens when a switch in that loop is opened?
Current stops throughout the loop, so both lamps go out
Current continues through one lamp but not the other
Both lamps stay lit but receive half the voltage
Current increases because the circuit has more resistance
15. After being rubbed, a charged balloon can stick to an electrically neutral wall. What best explains the attraction?
Charges in the wall shift slightly, placing opposite charge closer to the balloon
Gravity becomes stronger between the balloon and wall
The wall becomes a permanent source of electric current
The balloon removes all electrons from the wall's surface
16. A 100-watt lamp runs for 3 hours. How much electrical energy does it use in kilowatt-hours?
0.3 kilowatt-hours
0.03 kilowatt-hours
3 kilowatt-hours
300 kilowatt-hours