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प्रश्न
State the energy transformation on the following:
Electricity is obtained from solar energy.
उत्तर
Light energy into electrical energy
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संबंधित प्रश्न
When do we say that work is done?
State two conditions when no work is done by a force.
What are the quantities on which the amount of work done depends? How are they related to work?
Why is the work done on an object moving with uniform circular motion zero?
The velocity of a car increases from 54 km/hr to 72 km/hr. How much is the work done if the mass of the car is 1500 kg?
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
The work done on an object does not depend on ______.
What is the work done when the object acted upon by a force remains at rest?
State the energy changes which take place when An electric bulb glows when it is connected to a source of electric current.
State the energy changes which take place when A toy car with a wound spring moves on ground.
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
Name the material commonly used for the manufacturing of solar cells.
(i) A 200g ball is thrown vertically upward with an initial velocity of 30 ms-1. Draw a velocity-time graph for the motion of ball.
(ii) How long will the ball take to reach the highest point?
(iii) What will be the kinetic energy of ball, when it returns to the starting point, neglecting the air resistance?
(iv) What will be the potential energy of ball at highest point?
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A wind-mill is lifting water from a well.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A green plant is carrying out photosynthesis.
