
What is the formula for mobility?
Important Questions on Current Electricity



Three resistors having resistances and are connected as shown in the given circuit. The ratio of currents in terms of resistances used in the circuit is :


The magnitude of electric field at every point of the conductor is: (resistivity of magnesium )



The potential difference between points and of adjoining figure is


Shown in the figure is a semicircular metallic strip that has thickness and resistivity . Its inner radius is and outer radius is . If a voltage is applied between its two ends, a current flows in it. In addition, it is observed that a transverse voltage develops between its inner and outer surfaces due to purely kinetic effects of moving electrons (ignore any role of the magnetic field due to the current). Then (figure is schematic and not drawn to scale)



A conducting wire of length , area of cross-section and electric resistivity is connected between the terminals of a battery. A potential difference is developed between its ends, causing an electric current. If the length of the wire of the same material is doubled and the area of cross-section is halved, the resultant current would be___



In the circuit shown below, the key is pressed at time . Which of the following statement(s) is(are) true?

A variable current flows through a resistor for . Time dependence of the current is shown in the graph.



