Maths MCQs for AD (ASF)
Q11. Ideal transformer efficiency:
- A) Less than 90%
- B) Equal to 100%
- C) Greater than 100%
- D) Zero
Answer: B
An ideal transformer has no losses, so efficiency is 100%.
Q12. In an R-L circuit, current lags due to:
- A) Resistance
- B) Inductance
- C) Capacitance
- D) Conductance
Answer: B
Inductance causes current to lag behind voltage.
Q13. Relay using electromagnetic attraction:
- A) Thermal relay
- B) Distance relay
- C) Induction relay
- D) Overcurrent relay
Answer: D
Overcurrent relays operate using electromagnetic force when current exceeds limit.
Q14. Step-up transformer increases:
- A) Power
- B) Frequency
- C) Voltage
- D) Efficiency
Answer: C
Step-up transformer increases voltage while decreasing current.
Q15. Purpose of earthing:
- A) Increase current
- B) Improve efficiency
- C) Protect equipment and personnel
- D) Reduce voltage
Answer: C
Earthing provides safety by directing fault current to ground.
Q16. Opposition by inductor to AC is:
- A) Resistance
- B) Inductive reactance
- C) Capacitance
- D) Conductance
Answer: B
Inductive reactance increases with frequency.
Q17. Collector region is designed to:
- A) Reduce noise
- B) Handle higher voltage
- C) Increase base current
- D) Reduce gain
Answer: B
Collector must withstand high reverse voltage.
Q18. Condenser function in power plant:
- A) Increase pressure
- B) Convert steam to water
- C) Preheat water
- D) Remove gases
Answer: B
Condenser converts exhaust steam into water.
Q19. kVA measures:
- A) Active power
- B) Reactive power
- C) Apparent power
- D) Mechanical power
Answer: C
Apparent power = Voltage × Current.
Q20. Current in PN junction flows due to:
- A) Minority carriers
- B) Majority carriers
- C) Ions
- D) Free electrons only
Answer: B
Majority carriers dominate conduction in forward bias.
Management Trainee Electrical
