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प्रश्न
List some of the practical applications of an electromagnet.
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उत्तर
Electromagnets are used to lift heavy loads of scrap iron etc., to separate magnetic substances from non-magnetic ones and in devices like the electric bell, telegraphs, telephones, loud speakers, etc.
संबंधित प्रश्न
An emf of 2V is induced in a coil when the current in it is changed from 0A to 10A in 0·40 sec. Find the coefficient of self-inductance of the coil.
When current is 'switched on' and 'switched off' in a coil, a current is induced in another coil kept near it. What is this phenomenon known as?
When the magnet shown in the diagram below is moving towards the coil, the galvanometer gives a reading to the right.
() What is the name of the effect being produced by the moving magnet?
(2) State what happens to the reading shown on the galvanometer when the magnet is moving away from the coil.
(3) The original experiment is repeated. This time the magnet is moved towards the coil at a great speed. State two changes you would notice in the reading on the galvanometer.
How is the working of an electric bell affected, if alternating current be used instead of direct current?
- What kind of energy change takes place when a magnet is moved towards a coil having a galvanometer at its ends?
- Name the phenomenon.
In which of the following case does the electromagnetic induction occur?
The current is stopped in a wire held near a loop of wire .
State Fleming’s Right Hand Rule.
Answer the following:
State the principles of the electric motor and electric generator.
A coil of 200 turns carries a current of 4 A. If the magnetic flux through the coil is 6 x 10-5 Wb, find the magnetic energy stored in the medium surrounding the coil.
A coil of one turn is made of a wire of certain length and then from the same length, a coil of two turns is made. If the same current is passed in both the cases, then the ratio of the magnetic inductions at their centres will be:
