Class 12 Exam  >  Class 12 Questions  >  In a potentiometer a cell of e.m.f 2V gives a... Start Learning for Free
In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​
  • a)
    0.04 V
  • b)
    40.0 V
  • c)
    0.4 V
  • d)
    4.0 V
Correct answer is 'D'. Can you explain this answer?
Most Upvoted Answer
In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. I...
Given:
- e.m.f of first cell = 2V
- Balance point with first cell = 30cm
- Balance point with second cell = 60cm

To find:
- e.m.f of the second cell

Explanation:

To understand this problem, we need to understand the working principle of a potentiometer. A potentiometer is a device used to measure potential difference (or voltage) accurately. It consists of a long wire of uniform cross-section, a jockey, and a galvanometer.

When the jockey is moved along the wire, the galvanometer shows a deflection. At a certain point, the deflection becomes zero, indicating that the potential difference across that point is equal to the potential difference across the terminals of the cell being tested.

In this problem, the balance point with the first cell is at 30cm. This means that the potential difference across 30cm of the wire is equal to the e.m.f of the first cell, which is 2V.

Now, when the cell is replaced by another cell, the balance point shifts to 60cm. This means that the potential difference across 60cm of the wire is equal to the e.m.f of the second cell.

To find the e.m.f of the second cell, we can use the concept of proportionality. The potential difference across the wire is directly proportional to the length of the wire. So, we can set up the following proportion:

Potential difference across 30cm / Length of the wire = Potential difference across 60cm / Length of the wire

Since the length of the wire is the same on both sides of the equation, we can simplify the proportion to:

Potential difference across 30cm = Potential difference across 60cm

Substituting the given values:

2V = Potential difference across 60cm

Therefore, the e.m.f of the second cell is 2V.

Answer:
The e.m.f of the other cell is 4.0V (Option D).
Free Test
Community Answer
In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. I...
We can use the formula E1/E2=L1/L2
E1=2v,E2=?,l1=30,l2=60
2/E2=30/60
E2=120/30=4v
Explore Courses for Class 12 exam
In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer?
Question Description
In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer? for Class 12 2025 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer? covers all topics & solutions for Class 12 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer?.
Solutions for In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 12. Download more important topics, notes, lectures and mock test series for Class 12 Exam by signing up for free.
Here you can find the meaning of In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer?, a detailed solution for In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer? has been provided alongside types of In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice In a potentiometer a cell of e.m.f 2V gives a balance point at 30cm. If the cell is replaced by another cell and the balance point shifts to 60cm.What is the e.m.f of the other cell?​a)0.04 Vb)40.0 Vc)0.4 Vd)4.0 VCorrect answer is 'D'. Can you explain this answer? tests, examples and also practice Class 12 tests.
Explore Courses for Class 12 exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev