1. What is the equivalent resistance of two resistors, R1R_1R1 and
R2R_2R2, connected in parallel?
A. R=R1+R2R = R_1 + R_2R=R1+R2
B. R=R1R2R1+R2R = \frac{R_1 R_2}{R_1 + R_2}R=R1+R2R1R2
C. R=1R1+R2R = \frac{1}{R_1 + R_2}R=R1+R21
D. R=R1+R22R = \frac{R_1 + R_2}{2}R=2R1+R2
Answer: b) R=R1R2R1+R2R = \frac{R_1 R_2}{R_1 +
R_2}R=R1+R2R1R2
Rationale: The formula for two resistors in parallel is
1Req=1R1+1R2\frac{1}{R_{eq}} = \frac{1}{R_1} +
\frac{1}{R_2}Req1=R11+R21, which simplifies to R=R1R2R1+R2R
= \frac{R_1 R_2}{R_1 + R_2}R=R1+R2R1R2.
2. What is the effect of increasing the temperature on the resistance of a
conductor?
A. Increases resistance
B. Decreases resistance
C. No effect
D. Causes current to reverse direction
Answer: a) Increases resistance
,Rationale: As temperature increases, the atoms in the conductor vibrate
more, hindering the flow of electrons, thus increasing resistance.
3. The main function of an electrical transformer is to:
A. Store electrical energy
B. Convert AC to DC
C. Change voltage levels
D. Regulate current flow
Answer: c) Change voltage levels
Rationale: Transformers are used to step up or step down the voltage
levels in alternating current circuits.
4. Which of the following devices is used to control the flow of current
in a circuit?
A. Resistor
B. Switch
C. Capacitor
D. Inductor
Answer: b) Switch
Rationale: A switch is used to open or close a circuit, controlling the
flow of current.
5. What does a step-down transformer do?
, A. Increases voltage
B. Decreases voltage
C. Changes DC to AC
D. Reduces current
Answer: b) Decreases voltage
Rationale: A step-down transformer reduces the voltage from a higher
level to a lower level.
6. In a parallel circuit, if the resistance of one resistor is increased, the
total current in the circuit will:
A. Decrease
B. Increase
C. Stay the same
D. Become zero
Answer: b) Increase
Rationale: In a parallel circuit, adding resistance to one path increases
the total resistance slightly, but the current tends to increase because
other paths for current are available.
7. If the resistance in a circuit is halved while the voltage remains
constant, the current will:
A. Double
B. Remain the same
R2R_2R2, connected in parallel?
A. R=R1+R2R = R_1 + R_2R=R1+R2
B. R=R1R2R1+R2R = \frac{R_1 R_2}{R_1 + R_2}R=R1+R2R1R2
C. R=1R1+R2R = \frac{1}{R_1 + R_2}R=R1+R21
D. R=R1+R22R = \frac{R_1 + R_2}{2}R=2R1+R2
Answer: b) R=R1R2R1+R2R = \frac{R_1 R_2}{R_1 +
R_2}R=R1+R2R1R2
Rationale: The formula for two resistors in parallel is
1Req=1R1+1R2\frac{1}{R_{eq}} = \frac{1}{R_1} +
\frac{1}{R_2}Req1=R11+R21, which simplifies to R=R1R2R1+R2R
= \frac{R_1 R_2}{R_1 + R_2}R=R1+R2R1R2.
2. What is the effect of increasing the temperature on the resistance of a
conductor?
A. Increases resistance
B. Decreases resistance
C. No effect
D. Causes current to reverse direction
Answer: a) Increases resistance
,Rationale: As temperature increases, the atoms in the conductor vibrate
more, hindering the flow of electrons, thus increasing resistance.
3. The main function of an electrical transformer is to:
A. Store electrical energy
B. Convert AC to DC
C. Change voltage levels
D. Regulate current flow
Answer: c) Change voltage levels
Rationale: Transformers are used to step up or step down the voltage
levels in alternating current circuits.
4. Which of the following devices is used to control the flow of current
in a circuit?
A. Resistor
B. Switch
C. Capacitor
D. Inductor
Answer: b) Switch
Rationale: A switch is used to open or close a circuit, controlling the
flow of current.
5. What does a step-down transformer do?
, A. Increases voltage
B. Decreases voltage
C. Changes DC to AC
D. Reduces current
Answer: b) Decreases voltage
Rationale: A step-down transformer reduces the voltage from a higher
level to a lower level.
6. In a parallel circuit, if the resistance of one resistor is increased, the
total current in the circuit will:
A. Decrease
B. Increase
C. Stay the same
D. Become zero
Answer: b) Increase
Rationale: In a parallel circuit, adding resistance to one path increases
the total resistance slightly, but the current tends to increase because
other paths for current are available.
7. If the resistance in a circuit is halved while the voltage remains
constant, the current will:
A. Double
B. Remain the same
