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प्रश्न
Write Fleming’s right hand thumb rule with the help of diagram.
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उत्तर
If a current-carrying straight conductor is held in our right hand such that the thumb points towards the direction of the current, then the curled fingers around the conductor will give the direction of the magnetic field.
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संबंधित प्रश्न
Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.
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A) `(qR)/(Bm)`
B)`(qm)/(Br)`
C) `(qBR)/m`
D) `m/(qBR)`
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Name two devices in which electromagnets are used and two devices where permanent magnets are used.
What is an electromagnet? Describe the construction and working of an electromagnet with the help of a labelled diagram.
The north-south polarities of an electromagnet can be found easily by using:
(a) Fleming's right-hand rule
(b) Fleming's left-hand rule
(c) Clock face rule
(d) Left-hand thumb rule
The direction of current in the coil at one end of an electromagnet is clockwise. This end of the electromagnet will be:
(a) north pole
(b) east pole
(c) south pole
(d) west pole
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Describe one experiment to demonstrate the phenomenon of electromagnetic induction.
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- The magnet is kept still after it has moved into the coil
- The magnet is then rapidly pulled out the coil.
- How would the observation in (i) of part (a) change if a more powerful magnet is used?
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Answer the following:
State the principles of the electric motor and electric generator.
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Fleming’s right hand rule.
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- State the reason for using galvanometer in the activity and why does its needle deflects momentarily when magnet is moved towards the coil.
- What would be observed in the galvanometer in a situation when the coil and the bar magnet both move with the same speed in the same direction? Justify your answer.
- State the conclusion that can be drawn from this activity.
Will there be any change in the momentary deflection in the galvanometer if number of turns in the coil is increased and a more stronger magnet is moved towards the coil?
OR
What is electromagnetic induction? What is observed in the galvanometer when a strong bar magnet is held stationary near one end of a coil of large number of turns? Justify your answer.
