A square metal loop of side 10 cm and resistance 1 Ω is moved with a constant velocity partly inside a magnetic field of 2 Wbm–², directed into the paper, as shown in the figure. This loop is connected to a network of five resistors each of value 3 Ω. If a steady current of 1 mA flows in the loop, then the speed of the loop is :
A wheel with ten metallic spockes each 0.50 m long is rotated with a speed of 120 rev/min in a plane normal to the earth’s magnetic field at the place. If the magnitude of the field is 0.4 Gauss, the induced e.m.f. between the axle and the rim of the wheel is equal to :
Using the formula for induced e.m.f. in a rotating conductor:
Substituting
Some magnetic flux is changed from a coil of resistance 10 ohm. As a result an induced
current is developed in it, which varies with time as shown in figure. The magnitude of
change in flux through the coil in webers is:
Two coils are at fixed locations. When coil 1 has no current and the current in coil 2 increases at the rate 15.0 A/s the emf in coil 1 in 25.0 mV, when coil 2 has no current and coil 1 has a current of 3.6 A, the flux linkage in coil 2 is:
Based on the problem in your editor, here is the solution in 3 lines without using the $ symbol:
Find Mutual Inductance (M): M = Induced EMF / (rate of change of current) = 25.0 mV / 15.0 A/s = 1.667 mH.
Calculate Flux Linkage: Flux = M × Current = 1.667 mH × 3.6 A = 6.00 mWb.
Result: The flux linkage in coil 2 is 6.00 mWb (Option 4).
Two circular coils can be arranged in any of the three situations shown in the figure. Their
mutual inductance will be :
Based on the visual arrangement of the coils, the mutual inductance is maximum in situation (a).
This is because the coils are placed co-axially (one above the other), allowing the maximum amount of magnetic flux from the primary coil to pass through the secondary coil, resulting in the highest coupling coefficient.
The network shown in the figure is a part of a complete circuit. If at a certain instant the current i is 5 A and is decreasing at the rate of 10³A/s then \(V_{B}-V_{A}\) is :
An ideal coil of 10H is connected in series with a resistance of 5Ω and a battery of 5V. 2 seconds after the connection is made, the current flowing in amperes in the circuit is :
In step-down transformer of turn ratio 6 : 1, an alkali accumulator of 12 V; 3A is connected to the primary. Then the voltage developed in its secondary is :
The voltage developed in the secondary is zero.
A transformer operates on the principle of mutual induction, which requires a changing magnetic flux produced by Alternating Current (AC). Since an alkali accumulator provides Direct Current (DC), the magnetic flux remains constant, and no electromotive force (EMF) is induced in the secondary coil.