A cell is connected to an ideal voltmeter, a switch S and a resistor R. The resistanceof R is 4.0 Ω.VRS 4.0 ΩWhen S is open the reading on the voltmeter is 12 V. When S is closed the voltmeterreads 8.0 V.(i) State the emf of the cell.

(c) The voltmeter is used in another circuit that contains two secondary cells.Vcell Bcell A10 V 1.0 Ω2.0 Ω4.0 VCell A has an emf of 10 V and an internal resistance of 1.0 Ω. Cell B has an emf of 4.0 Vand an internal resistance of 2.0 Ω.Calculate the reading on the voltmeter.

A cell of emf 90 V is connected across series combination of two resistors each of 100 Ω resistance. A voltmeter of resistance 400 Ω is used to measure the potential difference across one of the given resistors. The reading of the voltmeter will be:

n the circuit shown below, the voltage across the battery terminals is measured to be 12 V when the switch, S, is open. When S is closed, this voltage falls to 8 V and the resistor, R, is then dissipating a power of 100 W. The internal resistance of the battery in Ohms to two decimal places is:

A battery of emf 10 V and internal resistance 3 W is connected to aresistor. If the current in the circuit is 0.5 A, what is the resistanceof the resistor? What is the terminal voltage of the battery when thecircuit is closed?

The EMF of the cell : Ni(s) | Ni2+ (1.0M) || Au 3+ (1.0M) | Au (s) is[ given EoNi2+/Ni -0.25V; E° Au3+ / Au = +1.50V ]