Advertisements
Advertisements
प्रश्न
Define power.
Define the following:
Power
उत्तर
Power is defined as the rate of doing work or work done per second.
i.e., Power = `("Work done in joule")/("Times in second")`
or, p = `("W (in joule)")/("t (in second)")`
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 ______.
The blades of a windmill sweep out a circle of area A.
- If the wind flows at a velocity v perpendicular to the circle, what is the mass of the air passing through it in time t?
- What is the kinetic energy of the air?
- Assume that the windmill converts 25% of the wind’s energy into electrical energy, and that A = 30 m2, v = 36 km/h and the density of air is 1.2 kg m–3. What is the electrical power produced?
Rajan exerts a force of 150 N in pulling a cart at a constant speed of 10 m/s-1. Calculate the power exerted.
Power P= ............ /time taken.
1 H.P. is equal to
An electric pump has 2 kW power. How much water will the pump lift every minute to a height of 10 m?
If a 1200 W electric iron is used daily for 30 minutes, how much total electricity is consumed in the month of April?
Choose one or more correct alternatives.
Power is a measure of the ______.
- The rapidity with which work is done.
- Amount of energy required to perform the work.
- The slowness with which work is performed.
- Length of time.
What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it can complete the loop?.
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 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)
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)
Calculate the power of a crane in watts, which lifts a mass of 100 kg to a height of 10 m in 20s.
Unit of power used in mechanical engineering is ______.
Name the quantity which is measured in Wh.
Name the quantity which is measured in eV.