An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220V. What is the current in each case.

(i) An electric iron consumes energy at the rate of 420W when heating is at the maximum rate and 180W when heating is at the minimum rate. The applied voltage is 220 V. what is the current in each case? (ii) What is co-efficient of real expansion?

An inductor coil stores 32 J of magnetic field energy and dissiopates energy as heat at the rate of 320 W when a current of 4 A is passed through it. Find the time constant of the circuit when this coil is joined across on ideal battery.

The voltage between the plates of a parallel plate capacitor of capacitance 1.0 mu F is changing at the rate of 5 V s^(-1) . What is the displacement current in the capacitance ?

A capacitor of capacitance C is connected to a battery of emf (epsilon) at t=0 through a resistance R. Find the maximum rate at which energy is stored in the capacitor. When does the rate has this maximum value?

A coil of inductance 0.50 H and resistance 100Omega is connected to a 240 V, 50 Hz ac supply. a. What is the maximum current in the coil? . b. What is the time lag between the voltage maximum and the current maximum?

Two coils P and Q are at fixed position. When coil P has no current in coil Q increases at the rate of 5As^(-1) , the e.m.f. in coil P is 20 mV. What is the mutual inductance? When the coil Q has no current and coil P has a current of 3A, what is the flux linkage in coil Q?

A conducting wire ab of length l, resistance r and mass m starts sliding at t = 0 down a smooth, vertical, thick pair of connected rails as shown in . A uniform magnetic field B exists in the space in a diraction perpendicular to the plane of the rails. (a) Write the induced emf in the loop at an instant t when the speed of the wire is v. (b) what would be the magnitude and direction of the induced current in the wire? (c) Find the downward acceleration of the wire at this instant. (d) After sufficient time, the wire starts moving with a constant velocity. Find this velocity v_m. (e) Find the velocity of the wire as a function of time. (f) Find the displacement of the wire as a functong of time. (g) Show that the rate of heat developed inte wire is equal to the rate at which the gravitational potential energy is decreased after steady state is reached.

What is the resistance of heating element of the heater when 20 A current passing through it at a potential of 220 V ?