Advertisements
Advertisements
प्रश्न
If a 1200 W electric iron is used daily for 30 minutes, how much total electricity is consumed in the month of April?
Advertisements
उत्तर
Data: P = 1200 W, t = 30 days × `"30 minutes"/"day" xx (60 "s")/("minute") = 54000 "s"` W = ?
P = `"W"/"t"`
∴ W = Pt
∴ W = 1200 W × 54000 s
= 648 × 105 J
= 6.48 × 107 J
= `(6.48 xx 10^7 "J")/(3.6 xx 10^6)` units
= 18 units
APPEARS IN
संबंधित प्रश्न
A body is moving unidirectionally under the influence of a source of constant power. Its displacement in time t is proportional to ______.
A pump on the ground floor of a building can pump up water to fill a tank of volume 30 m3 in 15 min. If the tank is 40 m above the ground, and the efficiency of the pump is 30%, how much electric power is consumed by the pump?
Rajan exerts a force of 150 N in pulling a cart at a constant speed of 10 m/s-1. Calculate the power exerted.
1 H.P. = .........
Two coolies A and B do some work in time 1 minute and 2 minute respectively. The power spent is
1 H.P. is equal to
A pump raises water by spending 4×105J of energy in 10s. Find the power of the pump.
It takes 20 s for a girl A to climb up the stairs while girl B takes 15 s for the same job. Compare the work done .
An electric heater of power 3 kW is used for 10 h. How much energy does it consume? Express your answer in
- kWh,
- joule.
A wind-powered generator converts wind energy into electric energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed v, the electrical power output will be proportional to ______
A ball with a velocity of 5 ms−1 impinges at an angle of 60˚ with the vertical on a smooth horizontal plane. If the coefficient of restitution is 0.5, find the velocity and direction after the impact.
A quarter horse power motor runs at a speed of 600 r.p.m. Assuming 40% efficiency, the work done by the motor in one rotation will be
An engine develops 20 kW power. How much time will it take to lift a mass of 200 kg to a height of 50 m? (g = 10 m/s2)
An engine pumps up 200 kg of water through a height of 20 m in 10 seconds. If the efficiency of the engine is 80%. Calculate the power of the engine.
Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine? (g = 10 m/s2)
The average work done by a human heart while it beats once is 0.5 J. Calculate the power used by heart if it beats 72 times in a minute.
Calculate the power spent by a crane while lifting a load of mass 2000 kg, at velocity of 1.5 ms-1. (g = 10 ms-2)
Unit of power used in mechanical engineering is ______.
