
The EMF of a cell is:
A. The potential difference across its terminals.
B. The potential difference across its terminals when no current is passing through it.
C. The heat produced when the cell is connected across 1 ohm resistor.
D. The total work done per coulomb of electricity in a circuit in which the cell is connected.
Answer
515.4k+ views
Hint: The potential difference applied due to cell and the EMF of a cell is not the same thing. Potential difference is the measure of total energy between any two points. Ideally, potential difference is equal to EMF value. But in practical cases, the cell itself has some resistance, called the internal resistance of the cell. Hence the potential difference of cells is always less than or equal to the EMF value or the EMF is the largest value of potential difference.
Complete answer:
Since the potential difference for a real cell is always less than the EMF value, hence option A. is incorrect.
But if the circuit is opened, no current will flow through it. If there’s no current in the circuit, the voltage will not be affected by resistance as if there’s no current, resistance also can’t be experienced in the circuit. Hence in open circuit, potential difference and EMF are the same thing. Hence, option B. is correct.
Again, heat produced when connected across 1 ohm resistor is the energy and both energy and EMF are two different physical quantities.
For work done per unit charge (or coulomb), by definition, it means the potential of a region. This is irrespective of the resistance.
So, the correct answer is “Option D”.
Note:
Since the potential difference for a real cell is always less than the EMF value, hence option A. is incorrect.
But if the circuit is opened, no current will flow through it. If there’s no current in the circuit, the voltage will not be affected by resistance as if there’s no current, resistance also can’t be experienced in the circuit. Hence in open circuit, potential difference and EMF are the same thing. Hence, option B. is correct.
Again, heat produced when connected across 1 ohm resistor is the energy and both energy and EMF are two different physical quantities.
For work done per unit charge (or coulomb), by definition, it means the potential of a region. This is irrespective of the resistance, and hence option D. is also correct.
Complete answer:
Since the potential difference for a real cell is always less than the EMF value, hence option A. is incorrect.
But if the circuit is opened, no current will flow through it. If there’s no current in the circuit, the voltage will not be affected by resistance as if there’s no current, resistance also can’t be experienced in the circuit. Hence in open circuit, potential difference and EMF are the same thing. Hence, option B. is correct.
Again, heat produced when connected across 1 ohm resistor is the energy and both energy and EMF are two different physical quantities.
For work done per unit charge (or coulomb), by definition, it means the potential of a region. This is irrespective of the resistance.
So, the correct answer is “Option D”.
Note:
Since the potential difference for a real cell is always less than the EMF value, hence option A. is incorrect.
But if the circuit is opened, no current will flow through it. If there’s no current in the circuit, the voltage will not be affected by resistance as if there’s no current, resistance also can’t be experienced in the circuit. Hence in open circuit, potential difference and EMF are the same thing. Hence, option B. is correct.
Again, heat produced when connected across 1 ohm resistor is the energy and both energy and EMF are two different physical quantities.
For work done per unit charge (or coulomb), by definition, it means the potential of a region. This is irrespective of the resistance, and hence option D. is also correct.
Latest Vedantu courses for you
Grade 11 Science PCM | CBSE | SCHOOL | English
CBSE (2025-26)
School Full course for CBSE students
₹41,848 per year
Recently Updated Pages
Master Class 12 Economics: Engaging Questions & Answers for Success

Master Class 12 Maths: Engaging Questions & Answers for Success

Master Class 12 Biology: Engaging Questions & Answers for Success

Master Class 12 Physics: Engaging Questions & Answers for Success

Master Class 12 Business Studies: Engaging Questions & Answers for Success

Master Class 12 English: Engaging Questions & Answers for Success

Trending doubts
Which one of the following is a true fish A Jellyfish class 12 biology CBSE

Which are the Top 10 Largest Countries of the World?

a Tabulate the differences in the characteristics of class 12 chemistry CBSE

Why is the cell called the structural and functional class 12 biology CBSE

Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE

Derive an expression for electric potential at point class 12 physics CBSE
