Q. 244.2( 13 Votes )

# Five electric fans of 120 watts each are used for 4 hours. Calculate the electrical energy consumed in kilowatt hours.

Answer :

Given,

Power = 120 watts = 0.12 kW;

Time, t = 4 hr

Hence, the energy consumed by one fan = P × t

= 0.12 × 4

= 0.48 KWh

Hence, the energy consumed by 5 fans,

= 0.48 x 5

=2.4 kWh

Rate this question :

A boy weighing 40 kg carriers a box weighing 20 kg to the top of a building 15 m high in 25 seconds. Calculate the power. (g = 10 m/s^{2})

A man weighing 500 N carried a load of 100 N up a fighter of stairs 4 m high in 5 seconds. What is the power?

Lakhmir Singh & Manjit Kaur - PhysicsDefine power. Give the SI unit of power.

Lakhmir Singh & Manjit Kaur - PhysicsAn electric motor raises a load of 0.2 kg, at a constant speed, through a vertical distance of 3.0 m in 2 s. If the acceleration power stations and thermal power stations, alternators produce electricity

A. 0.3 B. 1.2

C. 3.0 D. 6.0

Lakhmir Singh & Manjit Kaur - PhysicsIn an experiment to measure his power, a student records the time taken by him in running in a flight of steps on a staircase. Use the following data to calculate the power of the student:

Number of steps = 28

Height of each step = 20 cm

Time taken = 5.4 s

Mass of student = 55 kg

Acceleration = 9.8 m s^{-2}

Due to gravity

Lakhmir Singh & Manjit Kaur - PhysicsHow many watts equal one horse power?

Lakhmir Singh & Manjit Kaur - Physics