Explore topic-wise MCQs in Electrical Engineering.

This section includes 43 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

The SI unit of power is?

A. kW(kilo-watt)
B. J/s(joules per second)
C. Ws(watt-second)
D. Ws(watt-second)d) J/h(joules per hour
Answer» C. Ws(watt-second)
2.

Calculate the work done in a resistor of 20 ohm carrying 5A of current in 3 hours.

A. 1.5J
B. 15J
C. 1.5kWh
D. 15kWh
Answer» D. 15kWh
3.

Calculate the power across each 10 ohm resistance.

A. 1000kW, 1000kW
B. 1kW, 1kW
C. 100W, 100W
D. 100kW, 100kW
Answer» C. 100W, 100W
4.

Calculate the power across each 20 ohm resistance.

A. 1000W, 1000W
B. 500W, 500W
C. 1000kW, 1000kW
D. 500kW, 500kW
Answer» C. 1000kW, 1000kW
5.

A current of 5A flows in a resistor of 2 ohms. Calculate the energy dissipated in 300 seconds in the resistor.

A. 15kJ
B. 15000kJ
C. 1500J
D. 15J
Answer» B. 15000kJ
6.

Calculate the power in the 20 ohm resistance.

A. 2000kW
B. 2kW
C. 200kW
D. 2W
Answer» C. 200kW
7.

The force required to tow a vehicle at constant velocity is directly proportional to the magnitude of velocity raised to the first power. It requires 1000 W to tow with a velocity of 10 m/s. How much power is required to tow at a velocity of 8 m/s?

A. 320 W
B. 640 W
C. 160 W
D. 80 W
Answer» C. 160 W
8.

A body of mass 3 kg starts from rest with a uniform acceleration of unknown magnitude. If the body has a velocity of 30 m/s in 6 seconds, what is the power consumed in 3 seconds?

A. 125 W
B. 225 W
C. 325 W
D. 425 W
Answer» C. 325 W
9.

A 200 kg wagon climbs up a hill of slope 30-degrees in 1 minute at a speed of 36 km/h. How much power is delivered by the engine if the frictional force is 25% of the weight of the car? (Assume g = 10m/s2)

A. 25 kW
B. 50 kW
C. 100 kW
D. 125 kW
Answer» B. 50 kW
10.

A 200 kg wagon climbs up a hill of slope 30-degrees in 1 minute at a speed of 10 m/s. How much power is delivered by the engine? (Assume g = 10m/s2)

A. 10 kW
B. 20 kW
C. 30 kW
D. 40 kW
Answer» C. 30 kW
11.

1000 kW of power is supplied to a motor. 90% of this is transmitted to a machine operating at 80% efficiency. The machine lifts an object of 10-tons with a velocity _____ m/s. (Assume g = 10m/s2)

A. 2
B. 4
C. 6
D. 8
Answer» D. 8
12.

A 2-ton vehicle travels at 20m/s on a road where the frictional force is 10% of the weight of the vehicle. What is the power required? (Assume g = 10m/s2)

A. 220 kW
B. 240 kW
C. 420 kW
D. 440 kW
Answer» E.
13.

A machine has a power of 20kW. How long will it take for it to lift a body of mass 10kg from the ground to a height of 100m? (Assume g = 10m/s2)

A. 1 second
B. 2 seconds
C. 3 seconds
D. 4 seconds
Answer» C. 3 seconds
14.

A motor is used to pump water from a depth of 5 m to fill a volume of 10 cubic meters in 5 minutes. If 50% of the power is wasted, what is the power of the motor? (Assume g = 10m/s2)

A. 1000/3 W
B. 3000/3 W
C. 5000/3 W
D. 10000/3 W
Answer» E.
15.

A motor is used to deliver water through a pipe. Let the motor have a power P initially. To double the rate of flow of water through the pipe, the power is increased to P’. What is the value of P’/P?

A. 2
B. 4
C. 6
D. 8
Answer» E.
16.

A machine gun fires 360 bullets per minute. Each bullet has a mass of 5 grams and travels at 600 m/s. What is the power of the gun? (Assume no loss of energy and 100% power transmission)

A. 300 W
B. 600 W
C. 900 W
D. 1800 W
Answer» D. 1800 W
17.

What are the units of power?

A. Newton
B. Joule
C. Watt
D. No units
Answer» D. No units
18.

Power is the time derivative of which quantity?

A. Energy
B. Acceleration
C. Velocity
D. Position
Answer» B. Acceleration
19.

Which of the following is not a unit of power?

A. erg/second
B. kgm2s-3
C. Horsepower
D. Joule
Answer» E.
20.

The force applied on a body can be given as F = 4i + 2j + 6k. The displacement of the body is given by s = 3i + 9k. Calculate the power at t = 2 seconds.

A. 66 W
B. 33 W
C. 30 W
D. 15 W
Answer» C. 30 W
21.

What is the unit of Bond’s constant?

A. kW mm1/2 s/kg
B. kW mm s/kg
C. kW mm1/2 kg/s
D. kW mm kg/s
Answer» B. kW mm s/kg
22.

Which of the following is the correct formula of Bond’s law?

A. \(\frac {P}{m}\) = kb\((\frac {1}{\sqrt {D_{sb}}} + \frac {1}{\sqrt {D_{sa}}}) \)
B. P = kb\((\frac {1}{\sqrt {D_{sb}}} – \frac {1}{\sqrt {D_{sa}}}) \)
C. \(\frac {P}{m}\) = kb\((\frac {1}{\sqrt {D_{sb}}} – \frac {1}{\sqrt {D_{sa}}}) \)
D. P = kb\((\frac {1}{\sqrt {D_{sb}}} + \frac {1}{\sqrt {D_{sa}}}) \)
Answer» D. P = kb\((\frac {1}{\sqrt {D_{sb}}} + \frac {1}{\sqrt {D_{sa}}}) \)
23.

What are the dimensions of power?

A. [ML2T-3]
B. [ML2T-1]
C. [ML1T-3]
D. [ML3T-3]
Answer» C. [ML1T-3]
24.

What is the unit of Kick’s constant?

A. kg / kW
B. kW * s/kg
C. kW * kg/s
D. kg * s/kW
Answer» C. kW * kg/s
25.

Calculate the power required in Watts, if the work done can be given as w = 3t4 – 16t at t = 5 seconds.

A. 1795 W
B. 1420 W
C. 1484 W
D. 1675 W
Answer» D. 1675 W
26.

Work index is the gross energy required to reduce very large feed to a size such that, 65 percent of the product passes through a 100 – µm mesh screen.

A. True
B. False
Answer» C.
27.

Using Rittinger’s law, calculate the power required to crush 12 ton/hr of rocks, if 10 ton/hr rocks were crushed at a power of 9 hp. The diameter of the rocks was reduced from 3 cm to 0.5 cm in each case.

A. 10.7 hp
B. 11 hp
C. 10.8 hp
D. 12 hp
Answer» E.
28.

Automatic switching OFF function is accomplished in MCB by ______

A. Relay
B. clutch
C. bimetallic-strip
D. diode
Answer» D. diode
29.

Full form of UPS is

A. Undersized Power Supply
B. Uninterrupted Power Supply
C. Uneven Power Supply
D. Unwanted Power Supply
Answer» C. Uneven Power Supply
30.

Phase information of UPS is of no use during

A. voltage dip
B. long sags
C. interruptions
D. All of the above
Answer» E.
31.

Consider the following statements regarding linear power supply :1. It requires a low-frequency transformer.2. It requires a high-frequency transformer.3. The transistor works in the active region.Which of the above statements is/are correct?

A. 1 only
B. 2 and 3 only
C. 1 and 3 only
D. 3 only
Answer» D. 3 only
32.

In which order the blocks appear in the block diagram of a complete regulated power supply unit?

A. Rectifier-regulation-filter-transformer-load
B. Transformer-rectifier-filter-regulator-load
C. Transformer-rectifier-regulator-filter-load
D. Rectifier-regulator-filter-transformer-load
Answer» C. Transformer-rectifier-regulator-filter-load
33.

An inverter module in a power supply converts

A. AC to DC
B. DC to AC
C. AC to AC
D. DC to DC
Answer» C. AC to AC
34.

In the SMPS regulator is accompanied by:

A. Duty cycle control
B. Regulator IC
C. Zener
D. Stabilizer
Answer» B. Regulator IC
35.

An offline UPS requires:

A. Inductor
B. Capacitor
C. Battery
D. Resistor
Answer» D. Resistor
36.

A water boiler of home is switched on to the a.c. mains supplying power at 230V/50Hz. The frequency of instantaneous power consumed by the boiler is

A. 0 Hz
B. 50 Hz
C. 100 Hz
D. 150 Hz
Answer» D. 150 Hz
37.

A solar water heater cannot be used to get hot water on a _________.

A. hot day
B. sunny day
C. windy day
D. cloudy day
Answer» E.
38.

CALCULATE_THE_WORK_DONE_IN_A_RESISTOR_OF_20_OHM_CARRYING_5A_OF_CURRENT_IN_3_HOURS.?$

A. 1.5J
B. 15J
C. 1.5kWh
D. 15kWh
Answer» D. 15kWh
39.

The_SI_unit_of_power_is?$

A. kW(kilo-watt)
B. J/s(joules per second)
C. Ws(watt-second)
D. J/h(joules per hour
Answer» C. Ws(watt-second)
40.

A current of 5A flows in a resistor of 2 ohms. Calculate the power in the resistor and the energy dissipated in 300 seconds.

A. 15kJ
B. 15000kJ
C. 1500J
D. 15J
Answer» B. 15000kJ
41.

Kilowatt-hour(kWh) is a unit of?

A. Current
B. Power
C. Energy
D. Resistance
Answer» D. Resistance
42.

A 250V bulb passes a current of 0.3A. Calculate the power in the lamp.

A. 75W
B. 50W
C. 25W
D. 90W
Answer» B. 50W
43.

Which of the following is not an expression power?

A. P=VI
B. P=I<sup>2</sup>R
C. P=V<sup>2</sup>/R
D. All of the mentioned
Answer» B. P=I<sup>2</sup>R