A lamp consumes 1000J of electrical energy in 10s. What is the power?

A family uses 8 kW of power, (a) 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? (b) Compare this area to that of the roof of a typical house.

What is the basis of obtaining electrical energy in fuel cell?

An electric bulb is connected to a 240 V generator. The current is 0.70 A. What is the power of the bulb?

A steam engine delivers 5.4 xx 10^8 J of work per minute and services 3.6 XX 10^8 J of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute?

An electron of charge 'e' at rest in accelerted in a uniform electric field E. It covers a distance x. What is the kinetic energy gained by the electron?

Why is electrical energy transmitted at high voltage from a distance power generating station?

A photo electric surface has work function 2eV. What is the maximum kinetic energy of the emitted photoelectrons ejected by light by wavelength 3000overset(@)A Given h=6.6xx10^(-34)J-S,e=1.6xx10^(-19)C . m_e=9g0^(-31)kg,C = 3xx10^8m//sec