Advertisements
Advertisements
प्रश्न
A bar magnet is moved along the axis of a copper ring placed far away from the magnet. Looking from the side of the magnet, an anticlockwise current is found to be induced in the ring. Which of the following may be true?
(a) The south pole faces the ring and the magnet moves towards it.
(b) The north pole faces the ring and the magnet moves towards it.
(c) The south pole faces the ring and the magnet moves away from it.
(d) The north pole faces the ring and the magnet moves away from it.
Advertisements
उत्तर
(b) The north pole faces the ring and the magnet moves towards it.
(c) The south pole faces the ring and the magnet moves away from it.
It can be observed that the induced current is in anti-clockwise direction. So, the magnetic field induced in the copper ring is towards the observer.
According to Lenz's law, the current induced in a circuit due to a change in the magnetic flux is in such direction so as to oppose the change in flux.
Two cases are possible:-
(1) The magnetic flux is increasing in the direction from the observer to the circular coil.
(2) The magnetic flux is decreasing in the direction from the coil to the observer.
So, from the above mentioned points, the following conclusions can be made:-
1. The south pole faces the ring and the magnet moves away from it.
2. The north pole faces the ring and the magnet moves towards it.
APPEARS IN
संबंधित प्रश्न
Predict the direction of induced current in the situation described by the following figure.
Show that Lenz's law is a consequence of conservation of energy.
Predict the directions of induced currents in metal rings 1 and 2 lying in the same plane where current I in the wire is increasing steadily.
The battery discussed in the previous question is suddenly disconnected. Is a current induced in the other loop? If yes, when does it start and when does it end? Do the loops attract each other or repel?
Consider the situation shown in figure. If the closed loop is completely enclosed in the circuit containing the switch, the closed loop will show _______________ .
Explain, with the help of a suitable example, how we can show that Lenz's law is a consequence of the principle of conservation of energy.
Lenz’s law is a consequence of the law of conservation of ______.
Which of the following statements is not correct?
2 A 40 kg boy whose legs are 4 cm in area and 50 cm long falls through a height of 2 m without breaking his leg bones. If the bones can withstand stress of 0.9 x 108 N/m2. The Young's modulus for the material of the bone is ______.
Young's modulus for aluminium is 7 × 1010 Pa. The force needed to stretch an aluminium wire of diameter 2 mm and length 800 mm by 1 mm is ______.
For a coil having L = 2 mH, current flows at the rate of 10-3 AIS. The e.m.f induced is
Consider a metal ring kept on top of a fixed solenoid (say on a carboard) (Figure). The centre of the ring coincides with the axis of the solenoid. If the current is suddenly switched on, the metal ring jumps up. Explain
Consider a metal ring kept (supported by a cardboard) on top of a fixed solenoid carrying a current I (Figure). The centre of the ring coincides with the axis of the solenoid. If the current in the solenoid is switched off, what will happen to the ring?
Predict the direction of induced current in the situation described by the following figure.
Use Lenz’s law to determine the direction of induced current in the situation described by the figure.
A circular loop being deformed into a narrow straight wire.
