Advertisements
Advertisements
प्रश्न
Name the material commonly used for the manufacturing of solar cells.
Advertisements
उत्तर
Silicon and Gallium. Solar cell produces d.c. current. State whether a solar cell produces a.c. or d.c. current.
संबंधित प्रश्न
Explain briefly why the work done by a fielder when he takes a catch in a cricket match is negative.
A box of weight 150 kgf has gravitational potential energy stored in it equal to 14700 J. Find the height of the box above the ground. (Take g = 9.8 N kg-1)
A force of 50 N acts on a body and moves it a distance of 4 m on horizontal surface. Calculate the work done if the direction of force is at an angle of 60° to the horizontal surface.
A block of mass 20 kg is pulled up a slope (fig.12) with a constant speed by applying a force of 500 N parallel to the slope. A and B are initial and final positions of the block.
(a) Calculate the work done by the force in moving the block from A and B.
(b) Calculate the potential energy gained by the block.
State the energy changes which take place when A toy car with a wound spring moves on ground.
Can two agents, doing the same work, have different power?
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Suma is swimming in a pond.
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
