A DC potentiometer uses a slide wire of 800 mm. A standard cell of emf 1.18 V obtains balance at 600 mm. A test cell is seen to obtain balance at 660 mm. The emf of the test cell is

This question was previously asked in
ISRO (VSSC) Technical Assistant Electrical 2017 Official Paper
View all ISRO Technician Papers >
  1. 1.00 V
  2. 1.30 V
  3. 1.50 V
  4. 1.70 V

Answer (Detailed Solution Below)

Option 2 : 1.30 V
Free
IREL Tradesman Trainee (Electrician): DC Generator Quiz
1.7 K Users
5 Questions 5 Marks 5 Mins

Detailed Solution

Download Solution PDF

Concept:

F1 J.P Madhu 16.05.20 D1

 In a potentiometer

  • E L R
  • Where,
    • E = emf of test cell
    • L = Balancing length of slide wire
    • R = Slide wire resistance

Also

  • \(\frac{{{E_1}}}{{{E_2}}} = \frac{{{L_1}}}{{{L_2}}} = \frac{{{R_1}}}{{{R_2}}}\)

Note:

● Potentiometer is a zero order circuit, because no energy storing element is there.

Calculation:

Given-

E1 = 1.18 V

1 = 600 mm

L2 = 660 mm

\(\frac{{1.18}}{{{E_2}}} = \frac{{600}}{{660}}\)

E2 = 1.30 V

Latest ISRO Technician Updates

Last updated on May 28, 2025

-> ISRO Technician recruitment notification 2025 has been released. 

-> Candidates can apply for the ISRO recruitment 2025 for Technicians from June 2. 

-> A total of 64 vacancies are announced for the recruitment of Technician. 

-> The selection of the candidates is based on their performance in the Written Exam and Skill Test. 

-> Candidates who want a successful selection must refer to the ISRO Technician Previous Year Papers to increase their chances of selection for the Technician post. 

Get Free Access Now
Hot Links: teen patti apk teen patti diya teen patti all teen patti master app