Chapter 12 Introduction to Electricity
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Ohm’s Law states which of the following? 1) _______
A) Voltage is proportional to current and inversely proportional to resistance.
B) Voltage is proportional to current and resistance.
C) Voltage is inversely proportional to current and resistance.
2) Kirchhoff’s first law states which of the following? 2) _______
A) Resistances of each leg of a junction are equal.
B) The sum of the voltages at a junction is equal to zero.
C) The sum of the currents at a junction is zero.
3) Kirchhoff’s second law states which of the following? 3) _______
A) The sum of the voltages at a circuit is equal to zero.
B) The sum of the currents at a circuit is zero.
C) Resistances of each leg of a circuit are equal.
4) Two 5-ohm resistors are placed in series in a 10-amp circuit. What is their total resistance? 4) _______
A) 10 ohms. B) 10 watt-ohms. C) 10 watts.
5) Two 5-ohm resistors are placed in parallel in a 10-amp circuit. What is their total resistance? 5) _______
A) 2.5 ohms B) 10 ohms. C) 5 ohms
6) How much power is produced by passing 10 amps through a 5-ohm resistor? 6) _______
A) 250 watts. B) 500 watts. C) 50 watts
7) How much apparent power is produced in a circuit by 50 amps at 100 volts with a power factor
of 80%?
7) _______
A) 5000 volt-amps. B) 4000 watts. C) 4000 farads.
8) How much real power is produced in a circuit by 50 amps at 100 volts with a power factor of
80%?
8) _______
A) 4000 watts. B) 4000 farads. C) 5000 volt-amps.
9) The resistance in circuit is 5 ohms, the capacitive reactance is 5 ohms, and the inductive reactance
is 5 ohms. What if the total reactance of the circuit?
9) _______
A) 5 ohms. B) 15 ohms. C) 10 ohms.
10) A three-phase circuit has a line–to-neutral voltage of 120 volts. What is the line–to-line voltage? 10)
______
A) 85 volts. B) 300 volts. C) 208 volts.
