Advertisements
Advertisements
प्रश्न
Give an illustration of determining direction of induced current by using Lenz’s law.
Advertisements
उत्तर
- Move the bar magnet towards the solenoid with north pole pointing solenoid.
- When the Magnetic flux increases in the coil, an induced current is produced, and the coil becomes a magnetic dipole.
- According to Lenz law, induced current opposes the movement of the north pole towards coil.
(a)
(b)
(c)
- It is possible if end nearer to magnet becomes the north pole, then it repels the north pole of the magnet and oppose the movement of the magnet.
- The direction of induced current is found by the right-hand thumb rule.
- When a bar magnet is withdrawn, the nearer end becomes south pole which attracts the north pole of the bar magnet, opposing the receding motion of the magnet.
7. Direction of induced current can be found from Lenz law.
APPEARS IN
संबंधित प्रश्न
Explain different ways to induce current in a coil.
A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 m s−1, at right angles to the horizontal component of the earth’s magnetic field, 0.30 × 10−4 Wb m−2.
- What is the instantaneous value of the emf induced in the wire?
- What is the direction of the emf?
- Which end of the wire is at the higher electrical potential?
Name two devices in which electromagnets are used and two devices where permanent magnets are used.
Consider the energy density in a solenoid at its centre and that near its ends. Which of the two is greater?
Calculate the dimensions of (a) \[\int \overrightarrow{E} . d \overrightarrow{l,}\] (b) vBl and (c) \[\frac{d \Phi_B}{dt}.\] The symbols have their usual meaning.
Using Ampere's law, obtain an expression for the magnetic induction near a current-carrying straight infinitely long wire.
A thin semi-circular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure.

The potential difference developed across the ring when its speed v , is
Show that Lenz’s law is in accordance with the law of conservation of energy.
A metal plate can be heated by ______.
In the given circuit, initially switch S1 is closed and S2 and S3 are open. After charging of capacitor, at t = 0, S1 is open and S2 and S3 are closed. If the relation between inductance capacitance and resistance is L = 4CR2 then the time (in sec) after which current passing through capacitor and inductor will be same is ______ × 10-4 N. (Given R = ℓn(2)mΩ, L = 2mH)

