Current Electri...

A beam contains 2 × 10⁸ doubly charged positive ions per cubic centimeter, all of which are moving with a speed of 10⁵ m/s. The current density is

In the circuit shown, the reading of ammeter when switch S is open and when switch S is closed respectively are

In the circuit as shown in figure the

Given figure shows a rectangular block with dimensions x, 2x and 4x. Electrical contacts can be made to the block between opposite pairs of faces (for example, between the faces labelled A–A, B–B and C–C). Between which two faces would the maximum electrical resistance be obtained (A–A : Top and bottom faces, B–B : Left and right faces, C–C : Front and rear faces)

A battery is connected to a uniform resistance wire AB and B is earthed. Which one of the graphs below shows how the current density J varies along AB?

A cylindrical metal wire of length l and cross sectional area S, has resistance R, conductance G, conductivity σ and resistivity ρ. Which one of the following expressions for σ is valid?

A potential divider is used to give outputs of 4 V and 8 V from a 12 V source. Which combination of resistances, (R₁ : R₂ : R₃) gives the correct voltages ?

Find equivalent resistance between A and B

Following figure shows four situations in which positive and negative charges move horizontally through a region and gives the rate at which each charge moves. Rank the situations according to the effective current through the region greatest first

A and B are two square plates of same metal and same thickness but length of B is twice that of A. Ratio of resistances of A and B is