Misc. Elecrical MCQs Asked in Various Exams:


Q1. One unit of electricity is

a) One Kilo volt
b) One Kilo Watt
c) One Kilo Watt Hour
d) One Kilo Amp Hour

Correct Answer: One Kilo Watt Hour

Q2. At low frequencies the material used for transformer core is

a) copper
b) silicon iron
c) soft iron
d) none

Correct Answer: copper

Q3. A moving charge produces:

a) an electric field only
b) a magnetic field only
c) Both an electric field only & a magnetic field only
d) None of these

Correct Answer: Both an electric field only & a magnetic field only

Q4. The efficiency of transformer is maximum when

a) copper loss= twice Iron loss
b) copper loss=half times Iron loss
c) copper loss=Iron Loss
d) no condition for maximum efficiency

Correct Answer: copper loss=Iron Loss

Q5. A series motor is best suited for driving

a) latches
b) cranes and hoists
c) shears and punches
d) machine tools

Correct Answer: cranes and hoists

Q6. When a 3 phase induction motor is switched on the rotor frequency is ______________

a) 50 Hz
b) same as supply frequency
c) same as slip frequency
d) zero

Correct Answer: same as supply frequency

Q7. The regulation of a synchronous motor is ____________

a) 0.01
b) 1
c) 0.5
d) 0

Correct Answer: 0

Q8.In a 3Phase star connected system, the line current is

a) equal to phase current
b) 1/√3 times phase current
c) √3 times phase current
d) 3 times phase current

Correct Answer: 1/√3 times phase current

Q9. The speed regulation of a synchronous motor is

a) positive
b) zero
c) negative
d) any of the these

Correct Answer: positive

Q10. The stator of a split phase type single phase induction motor is provided with

a) 3 windings
b) 2 windings
c) 1 winding
d) 6 windings

Correct Answer: 1 winding
Q11. Among the following statements which one is true? 
a) a.c. transmission is more efficient
b) d.c. transmission is more efficient
c) both are equally efficient
d) low voltage d.c. transmission is more efficient

Correct Answer: both are equally efficient

Q12. For measuring a very high resistance we should use

a) Kelvin's double bridge
b) Wheatstone bridge
c) Megger
d) None of these

Correct Answer: Megger

Q13. The pressure coil of a dynamometer type wattmeter is 
a) Highly inductive
b) Highly resistive
c) Purely resistive
d) Purely inductive

Correct Answer: Highly resistive

Q14. The Guage factor of a Resistance wire strain guage, is a measure of 
a) Sensitivity of the Guage
b) Dynamic range of displacement measure
c) Resolution
d) Resistivity

Correct Answer: Sensitivity of the Guage

Q15.The performance of Servomotors is ______________ Than stepper motors 
a) Very Accurate
b) Highly controlled by feedback
c) Both Very Accurate & Highly controlled by feedback
d) None of these

Correct Answer: Both Very Accurate & Highly controlled by feedback

Q16. High power amplification is achieved by the use of
 a) Magnetic amplifier
b) DC amplifier
c) DC generator
d) Amplidyne

Correct Answer: DC amplifier

Q17. A 6 V battery is connected to a 300Ω load. Under these conditions, it is rated at 40 Ah. How long can it supply current to the load?
a) 1000 h
b) 2000 h
c) 200 h
d) 4000 h

Correct Answer: 2000 h

Q18. A 12 V source has an internal resistance of 90 Ω . If a load resistance of 20 Ω is connected to the voltage source, the load power, PL is 
a) 2.38 mW
b) 2.38 W
c) 238 mW
d) 23.8 W

Correct Answer: 238 mW

Q19. Kirchhoff's second law is based on law of conservation of
 a) charge
b) energy
c) momentum
d) mass

Correct Answer: energy

Q20. During charging the specific gravity of electrolyte of a lead acid battery
 a) increases
b) decreases
c) remains same
d) becomes zero

Correct Answer: increases