Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
(i)According to Lenz's law, the polarity of emf induced in the coil always opposes the change in the magnetic flux responsible for production of induced emf.
(ii) Lenz's law is used to determine the direction of current induced in the closed circuit. Let us consider an example to illustrate it. When a north pole of a bar magnet is brought closer to a coil, as shown in figure, the amount of magnetic flux linked with the coil increases. So, the current induced in the coil is directed such that it opposes this change in magnetic flux responsible for production of induced current, which is possible only when the current induced in the coil is in anticlockwise direction of the observer on the side of the magnet.
Similarly, the direction of induced current can be found when north pole of bar magnet is moved away from the coil. As the magnetic flux in this case decreases, the induced current is in the clockwise direction.
\
APPEARS IN
संबंधित प्रश्न
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.
Use Lenz’s law to determine the direction of induced current in the situation described by the figure:
A wire of irregular shape turning into a circular shape.
Predict the direction of induced current in a metal ring when the ring is moved towards a straight conductor with constant speed v. The conductor is carrying current I in the direction shown in the figure.
Which of the following statements is not correct?
Energy dissipate in LCR circuit in
A long solenoid ‘S’ has ‘n’ turns per meter, with diameter ‘a’. At the centre of this coil we place a smaller coil of ‘N’ turns and diameter ‘b’ (where b < a). If the current in the solenoid increases linearly, with time, what is the induced emf appearing in the smaller coil. Plot graph showing nature of variation in emf, if current varies as a function of mt2 + C.
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.
What happens whenever the magnetic flux through a closed circuit changes?
What would happen to the magnet if an induced South pole attracted an approaching N-pole without external effort?
What is the induced current path for an irregular loop moving out of an out-of-page magnetic field?
