Current Electricity · Physics · Class 12

Assertion (A) : The equivalent resistance between points A and B in the given network is 2R. Reason (R) : All the resistors are connected in parallel ...

A current of 0.8 A flows in a conductor of $$40 \Omega$$ for 1 minute. The heat produced in the conductor will be

A cell of emf $$E$$ is connected across an external resistance $$R$$. When current '$$I$$' is drawn from the cell, the potential difference across the...

Kirchhoff's first rule $$\Sigma$$I = 0 and second rule $$\Sigma$$IR = $$\Sigma$$E (where the symbols have their usual meanings) are respectively based...

The electric power consumed by a 220 V $$-$$ 100 W bulb when operated at 110 V is

If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a -

A potential difference of 200 V is maintained across a conductor of resistance 100 $$\Omega$$. The number of electrons passing through it in 1s is

In a dc circuit the direction of current inside the battery and outside the battery respectively are -

A car battery is charged by a 12 V supply, and energy stored in it is 7.20 $$\times$$ 105 J. The charge passed through the battery is -

If n, e, $$\tau$$ and m have their usual meanings, then the resistance of a wire of length l and cross-sectional area A is given by -

Two sources of equal emf are connected in series. This combination is, in turn connected to an external resistance R. The internal resistance of two s...

The equivalent resistance between A and B of the network shown in figure is ...

Assertion (A) : Higher the range, lower is the resistance of an ammeter.Reason (R) : To increase the range of an ammeter additional shunt is added in ...

The points with the same potential are -

The current through branch bg is -

The power dissipated in R1 is -

The potential difference across R3 is -

The potential difference applied across a given conductor is doubled. How will this affect (i) the mobility of electrons and (ii) the current density ...

(a) Briefly describe how the current sensitivity of a moving coil galvanometer can be increased. (b) A galvanometer shows full scale deflection for cu...

(a) (i) Explain how free electrons in a metal at constant temperature attain an average velocity under the action of an electric field. Hence obtain a...

Briefly explain why and how a galvanometer is converted into an ammeter.

Define current density and relaxation time. Derive an expression for resistivity of a conductor in terms of number density of charge carriers in the c...