An electromagnet attracts a few pins when connected to a source of current. However when the current is disconnected, it stops attracting the pins.

When filament current is increased

When an a.c source is connected across a resistor

An AC source is connected to a capacitor. The current in the current is I. Now a dielectric slab is inserted into the capacitor , then the new current is

When an inductor coil is connected to an ideal battery of emf 10V, a constant current 2.5 A flows. When the same inductor coil is connected to an ac source of 10V and 50 HZ then the current is 2A. Find out the inductance of the coil.

When connected across the terminals of a cell, a voltmeter measures 5 V and a connected ammeter measures 10 A of current. A resistance of 2 ohm s is connected across the terminals of the cell. The current flowing through this resistance will be

Eddy current are produce when

Two bulbs when connected in parallel to a source take 60 W each, the power consumed, when they are connected in series with the same source is

In a transistor the current amplification alpha is '0.9', when connected in common base configuration. Now if the same transistor is connected in common emitter configurations and the change in ouput current is 4.5 mA, then the corresponding charnge in the input current is

When no current is passed through a conductor,

The conduction current is the same as displacement current when the source is