The following two questions refer to a circuit of a resistor and a battery.
1. What happens to the current when the voltage is doubled and the resistance remains the same?
(A) It is quartered.
(B) It is quadrupled.
(C) It is halved.
(D) It is doubled.
(E) It remains the same.
2. What happens to the power dissipated in the resistor when the resistance is quadrupled and the voltage
remains the constant?
(A) It is doubled.
(B) It is quadrupled
(C) It is halved
(D) It is quartered.
(E) It remains the same.
3. Which of the following affects the resistance of a wire?
I. The material from which it is made.
(A) I only
(B) II only
II. The length of the wire.
(C) I & II only
III. The diameter of the wire.
(D) I & III only
(E) I, II and III
4. Two resistors R1 and R2 are identical, but the voltage across R1 is half the voltage across R2. What is the
ratio of the current through R1 to the current through R2?
(A) 1:4
(B) 1:2
(C) 1:1
(D) 2:1
(E) 4:1
Questions 5 and 6 refer to two identical resistors arranged in parallel.
5. If a third identical resistor is added in parallel, what is the ratio of the new equivalent resistance to the old?
(A) 4:9
(B) 2:3
(C) 1:1
(D) 3:2
(E) 9:4
6. When the third identical resistor is added in parallel with the other two, what is the ratio of the new total
current to the old total current? Assume the voltage remains constant.
(A) 4:9
(B) 2:3
(C) 1:1
(D) 3:2
(E) 9:4
7. How much heat is produced in a 5 Ω resistor in 10 s when a current of 2 A flows through it?
(A) 2 J
(B) 10 J
(C) 20 J
(D) 100 J
(E) 200 J
8. Two identical light bulbs are connected in parallel. The battery can supply a voltage of 6 V. What is the
voltage across each bulb?
(A) 3 V
(B) 2 V
(C) 12 V
(D) 6V
9. Two identical light bulbs are connected in parallel. The current from the battery is 4 A. The current through
one bulb is 1 A. What is the current though the other bulb?
(A) 4 A
(B) 1 A
(C) 3 A (D) 2 A
10. If electricity costs $0.15 per kWH, how much will it cost to use a 13 W CFL for 24 hours a day for 1 year?
(A) $114
(B) $17
(C) $17000
(D) $47
(E) $0.05