A wire in the form of a tightly wound solenoid is connected to a DC source, and carries a current. If the coil is stretched so that there are gaps between successive elements of the spiral coil, will the current increases or decrease? Explain.

A solenoid is connected to a battery so that a steady current flows through it. If an iron core is inserted into the solenoid, will the current increase or decrease ? Explain.

An electric heater coil if connected to a 230 V source if the resistance of the heater coil is 220 ohm. Find the current.

An electric heater coils is connect to a 220 V source. If the resistance of the heater coil is 220 ohm. Find the current.

A capacitor has some dielectric between its plates, and the capacitor is connected to a DC source. The battery is now disconnected and then the dielectric is removed. State whether the capacitance, the energy stored in it, electric field, charged stored and the voltage will increase, decrease or remains constant.

A coil of inductance 0.50 H and resistance 100 ohm is connected to a high frequency supply (240 V, 10 kHz). (a) Obtain the maximum current in the coil. (b) what is the time lag between voltage maximum and the current maximum. Hence, explain the statement that at very high frequency, an inductor in a circuit nearly amounts to an open circuit. How does an inductor behave in a dc circuit after the steady state?

A uniform conducting wire of length 12a and resistance R is wound up as a current carrying coil in the shape of a square of side a. The coil is connected to a voltage source V_0 . Find the magnetic moment of the coils in each case.

A second coil of 300 turns is wound closely on the toroid above. If the current in the primary coil is increased from zero to 2.0 A in 0.05 s, obtain the induced e.m.f. in the second coil.

The magnetic field of a given length of wire carrying a current of a single turn circular coil at centre is B, then its value for two turns for the same wire when same current passing through it is

A circular coil of wire consisting of 100 turns, each of radius 8.0 cm carries a current of 0.40 A. What is the magnitude of the magnetic field B at the centre of the coil?