Advertisements
Advertisements
प्रश्न
Advertisements
उत्तर
The Sl unit of power is `watt'.
If 1 joule of work is done in 1 second, Watt = `(1J)/(1S)` the power is said to be 1 watt.
APPEARS IN
संबंधित प्रश्न
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?
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?
A family uses 8 kW of power.
- Direct solar energy is incident on the horizontal surface at an average rate of 200 W per square meter. If 20% of this energy can be converted to useful electrical energy, how large an area is needed to supply 8 kW?
- Compare this area to that of the roof of a typical house.
Rajan exerts a force of 150 N in pulling a cart at a constant speed of 10 m/s-1. Calculate the power exerted.
The S.I. unit of power is ..........
1 H.P. = .........
A pump raises water by spending 4×105J of energy in 10s. Find the power of the pump.
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
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.
Name the quantity which is measured in Wh.
