The process by which a changing magnetic filed in conductor induces a current in another conductor is called electromagnetic induction . The scientist Michael Faraday did many experiments in this field . Whenever there is a relative motion between a magnet and a coil , a current is induced in the coil due to the change in the magnetic field associated with it . This process of producing induction current is known as electromagnetic induction .
Name the rule which gives the direction of induced current .
a ) Fleming's left hand rule
b ) Right hand grip rule
c ) Fleming's right hand rule
d ) Maxwell cork screw rule
( ii ) The form of conversion of energy utilized in electromagnetic induction is from
a ) Light energy into electrical
b ) mechanical energy into electrical c ) electrical energy into mechanical d ) Mechanical energy into magnetic
( iii ) How can the amount of current be increased in a coil of wire ?
a ) By increasing speed of motion of magnet
b ) By increasing number of turns in the coil
c ) by increasing the strength of sliding magnet
d ) all of the above
( iv ) Identify the instrument works on the basis of electromagnetic induction
a ) electric motor
b ) Transformer
c ) electric fan
d ) electric heater
( v ) The deflection in the galvanometer when battery plugged in and plugged off indicate the presence of
a ) energy
b ) power
c ) current
d ) resistance
Answers
Answer 1:
(c) Fleming's right hand rule.
Understanding this rule;
Hold you thumb, forefinger and middle finger in such a way that these all are mutually perpendicular to each other and if your forefinger is giving the direction of magnetic field, thumb is showing the direction of motion of conductor only then your middle finger will give the direction of induced current.
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Answer 2:
(b) Mechanical energy into electrical energy.
Explanation:
The moving field lines are inducing some current, this means that Mechanical energy ( movement of coil) has some current ( detected by galvanometer), which can be used as energy.
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Answer 3:
(d) All of these
Explanation:
When you move magnet at high speed, magnetic field lines will also be changed at high speed and thus more current is induced.
Increasing number of turns of copper wire of coil and increasing the strength of the moving magnetic will increase magnetic field lines and we know that more the magnetic field more will be the induced current.
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Answer 4:
(b) Transformer
Explanation:
Transformer is a device which is used to produce electricity. Where a moving coil induces some amount of current which is used as electricity.
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Answer 5:
(c) Current
Explanation:
Whenever needle of galvanometer deflects, it shows that some amount of current is induced in the attached coil. The main function of galvanometer is to detect the presence of current.