1. Which of the following is a passive electronic component?
A. Transistor
B. Diode
C. Resistor
D. Operational Amplifier
Answer: C
(A resistor is a passive component because it does not amplify or generate energy.)
2. The SI unit of capacitance is:
A. Henry (H)
B. Farad (F)
C. Ohm (Ω)
D. Volt (V)
Answer: B
(The SI unit of capacitance is the Farad (F).)
3. What is the primary function of a diode?
A. To amplify signals
B. To store energy
C. To allow current to flow in one direction only
D. To convert DC to AC
Answer: C
(A diode allows current to flow in one direction only, acting as a rectifier.)
4. In an NPN transistor, current flows:
A. From emitter to base
B. From base to collector
C. From collector to emitter
D. From emitter to collector
Answer: D
(In an NPN transistor, current flows from the emitter to the collector when it is in active mode.)
5. Ohm’s Law is given by:
A. V=IRV = IR
B. V=I/RV = I/R
C. V=R/IV = R/I
D. V=I2RV = I^2R
Answer: A
(Ohm’s Law states that voltage (VV) is equal to the current (II) multiplied by the resistance (RR).)
6. The resistance of a conductor depends on:
A. Voltage and current
B. Length, cross-sectional area, and material of the conductor
C. Capacitance and inductance
D. Temperature only
Answer: B
(Resistance depends on the length, cross-sectional area, material, and temperature of the conductor.)
7. Which of the following is a semiconductor material?
A. Copper
B. Silicon
C. Aluminum
D. Glass
Answer: B
(Silicon is the most commonly used semiconductor material in electronics.)
8. What is the function of an inductor in an electronic circuit?
A. To resist the flow of current
B. To store electrical energy in a magnetic field
C. To amplify signals
D. To convert AC to DC
Answer: B
(An inductor stores energy in its magnetic field when current flows through it.)
9. The threshold voltage of a silicon diode is approximately:
A. 0.2 V
B. 0.7 V
C. 1.2 V
D. 5 V
Answer: B
(The threshold or forward voltage of a silicon diode is approximately 0.7 V.)
10. In an RC circuit, the time constant (τ\tau) is given by:
A. R+CR + C
B. RCRC
C. R/CR / C
D. R2CR^2C
Answer: B
(The time constant in an RC circuit is the product of resistance (RR) and capacitance (CC).)
11. Which of the following devices is used to convert AC to DC?
A. Inductor
B. Diode
C. Transformer
D. Capacitor
Answer: B
(A diode is used in rectifiers to convert AC to DC.)
12. The unit of electrical power is:
A. Volt
B. Ohm
C. Joule
D. Watt
Answer: D
(The SI unit of power is the Watt (W).)
13. What happens to the current in a series circuit if one component fails?
A. The current remains the same
B. The current increases
C. The current stops
D. The circuit becomes an open circuit
Answer: C
(In a series circuit, if one component fails, the current stops because the circuit becomes open.)
14. A Zener diode is primarily used for:
A. Current amplification
B. Signal modulation
C. Voltage regulation
D. Energy storage
Answer: C
(A Zener diode is used for voltage regulation by operating in its reverse breakdown region.)
15. Which law states that the sum of currents entering a node is equal to the sum of currents leaving the node?
A. Kirchhoff’s Voltage Law (KVL)
B. Ohm’s Law
C. Kirchhoff’s Current Law (KCL)
D. Faraday’s Law
Answer: C
(Kirchhoff’s Current Law (KCL) states that the total current entering a junction equals the total current leaving it.)
16. What does a capacitor store in an electronic circuit?
A. Current
B. Energy in the form of an electric field
C. Magnetic field energy
D. Heat
Answer: B
(A capacitor stores energy in the form of an electric field.)
17. Which of the following is a unipolar device?
A. Diode
B. Bipolar Junction Transistor (BJT)
C. Field-Effect Transistor (FET)
D. Transformer
Answer: C
(A Field-Effect Transistor (FET) is a unipolar device because it operates using either electrons or holes, but not both.)
18. Which of the following circuit configurations is used for voltage amplification?
A. Common Base
B. Common Emitter
C. Common Collector
D. Emitter Follower
Answer: B
(A common-emitter configuration is widely used for voltage amplification.)
19. The power dissipation in a resistor is calculated using:
A. P=VIP = VI
B. P=I2RP = I^2R
C. P=V2/RP = V^2/R
D. All of the above
Answer: D
(All of the formulas are correct depending on the known parameters.)
20. What is the function of a rectifier in an electronic circuit?
A. To amplify the signal
B. To convert AC to DC
C. To store energy
D. To filter noise
Answer: B