Advertisements
Advertisements
Question
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?
Advertisements
Solution
When the battery is suddenly disconnected, a current is induced in loop B due to a sudden change in the flux through it. It is only induced for a moment when the current suddenly falls to zero. There is no induced current after it has fallen to zero. According to Lenz's law, the induced current is such that it increases the decreasing magnetic field. So, if the current in loop A is in clockwise direction, the induced current in loop B will also be in clockwise direction. Hence, the two loops will attract each other.
APPEARS IN
RELATED QUESTIONS
State Lenz's law. Illustrate, by giving an example, how this law helps in predicting the direction of the current in a loop in the presence of a changing magnetic flux.
Describe a simple experiment (or activity) to show that the polarity of emf induced in a coil is always such that it tends to produce a current which opposes the change of magnetic flux that produces it.
What is the direction of induced currents in metal rings 1 and 2 when current I in the wire is increasing steadily?
A bar magnet is moved in the direction indicated by the arrow between two coils PQ and CD. Predict the directions of induced current in each coil.
Consider the situation shown in figure. If the switch is closed and after some time it is opened again, the closed loop will show ____________ .
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.
Consider the situation shown in figure. If the closed loop is completely enclosed in the circuit containing the switch, the closed loop will show _______________ .
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 ______.
A bar magnet is dropped through a copper ring acceleration of magnet is
Energy dissipate in LCR circuit in
For a coil having L = 2 mH, current flows at the rate of 10-3 AIS. The e.m.f induced is
Consider a magnet surrounded by a wire with an on/off switch S (Figure). If the switch is thrown from the off position (open circuit) to the on position (closed circuit), will a current flow in the circuit? Explain.
Predict the direction of induced current in the situation described by the following figure.
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.
In the diagram given below, a strong bar magnet is moving towards solenoid-2 from solenoid-1. The direction of induced current in solenoid-1 and that in solenoid-2, respectively, are through the directions:
