Advertisements
Advertisements
प्रश्न
State the unit of energy and define it.
उत्तर
The energy is measured in the same unit as work. Therefore the S.I. unit of energy is joule (symbol J).
A body is said to possess an energy of one joule if a force of 1 newton moves the body by a distance of 1 metre in the direction of force.
Another unit of energy is calorie (symbol cal) where 1 cal = 4.2 J. A bigger unit is kilo-calorie (symbol kcal) where 1 kcal = 1000 cal.
APPEARS IN
संबंधित प्रश्न
Fill in the blank
An electric fan converts electrical energy into ______ energy.
Fill in the blank
The ability to do work is called ______
Match the following columns
| COLUMN A | COLUMN B |
| 1. Running water | 1. heat energy |
| 2. Burning | 2. vibrations |
| 3.Energy | 3.atom bomb |
| 4.Sound energy | 4.kinetic energy |
| 5.Nuclear energy | 5.joule |
State two factors on which the potential energy of a body at a certain height above the ground depends.
Tick the most appropriate answer.
The force applied on a machine to do work is called the
Name two units of power bigger than watt.
The commercial unit of energy is :
Observe the picture and put a tick (✓) if work is done and put a cross (x) if work is not done.
 |
 |
 |
 |
 |
 |
Which one of the following requires wind energy?
A ball is dropped from a height of 10 m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back? (g = 10 m s–2)
