Advertisements
Advertisements
Question
State the factors on which the e.m.f of a cell depends.
Advertisements
Solution
The e.m.f. of different cell depends on the following factors:
(i) The material of the electrodes.
(ii) The electrolyte used in the cell.
It is to be noted that the e.m.f. of a cell does not depend on its shape or size.
RELATED QUESTIONS
An electric bulb of 300Ω draws a current of 0.4 A. Calculate the power of the bulb and the potential difference at its ends.
Explain the meaning of the term e.m.f. of a cell.
A battery o f e.m.f. 3 Vis connected in series with an ammeter, a 10 Ω coil of wire and with a parallel combination o f resistance of 3Ω and 6 Ω. Draw a circuit diagram for the above arrangement. What is the
(a) Resistance of the parallel combination?
(b) Reading on the ammeter?
( c) Potential difference across the 3Ω resistor?
( d) Current flowing through each resistor?
A cell of e.m.f. E and internal resistance r is used to send current I in an external resistance R. Write expressions for (i) the current drawn from the cell,
(ii) the terminal voltage V of the cell, and
(iii) the voltage drop across the internal resistance. How are E and V related?
A cell of e.m.f. 1.5 V and internal resistance 1.0 W is connected to two resistors of 4.0 W and 20.0 in series as shown in the figure: Calculate the:
(i) Current in the circuit.
(ii) Potential difference across the 4.0 ohm resistor.
(iii) Voltage drop when the current is flowing.
(iv) Potential difference across the cell.
The e.m.f of a cell is analogues to ______ of a pipe line.
Electrons in outer orbits are called free electrons.
Define the following:
Electromotive force (e.m.f.)
