A cell is connected to a resistor. What is the e.m.f of the cell equal to?
Correct answer: C. The work done in the circuit for each unit of charge that passes
- A. The potential difference across the resistor for each unit of current
- B. The power produced in the circuit for each unit of charge that passes
- C. The work done in the circuit for each unit of charge that passes
- D. The work done in the circuit for each unit of current
Explanation
The electromotive force (e.m.f) of a cell is the total energy supplied by the cell per unit charge, which means it is the work done to move a charge from the negative terminal to the positive terminal. This is why Option C is correct. Option A is incorrect because it describes potential difference, not e.m.f. Option B is incorrect because power is not directly related to e.m.f in terms of per unit charge. Option D confuses work done per unit current with e.m.f, which is more aligned with potential difference and resistance.
Last updated
About Current Electricity
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
Practise Current Electricity
1,052 free Current Electricity MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
0.75 A current flows through an iron wire when a battery of 1.5 volts is connected across its ends. The length of the wire 5.0 m and its cross-sectional area is 2.5 x 10^-7 m2. What is the resistivity of iron?
1.6 mA current is flowing in conducting wire then the number of electrons flowing per second
1 kilo ohm = _ ohm
1 microvolt is
1/Req = 1/Rl + 1/R2 + 1/R3 + ..... +1/Rn is the combination in