PHYSICS

JAMB 2011 - Question 37

Physics 2011 JAMB Past Questions - Question 37: Three similar cells each of e.m.f 2V and internal resistance 2Ω are connented in parallel , total e.m.f and total internal resistance

Choose the correct answers from the options given.
Three similar cells each of e.m.f 2V and internal resistance 2Ω are connented in parallel , total e.m.f and total internal resistance
A:
B:
C:
D:
Examkits App

Examkit's JAMB CBT App

Practice JAMB offline with our Online, PC and Mobile App

  • ✅ 25+ years of past questions (2000 to 2025)
  • ✅ Video solutions and explanation to questions
  • ✅ E-library
  • ✅ Study by topic
  • ✅ And more.

Correct Answer

D

Explanation

To find the total electromotive force (e.m.f) and total internal resistance of the three similar cells connected in parallel, we can use the following formulas:

Total e.m.f (E_total) = E_1 + E_2 + E_3
Total internal resistance (R_total) = R_1 // R_2 // R_3

Given that each cell has an e.m.f of 2V and an internal resistance of 2Ω, we can substitute these values into the formulas:

Total e.m.f (E_total) = 2V + 2V + 2V = 6V
Total internal resistance (R_total) = 2Ω // 2Ω // 2Ω

To calculate the total internal resistance, we need to find the equivalent resistance of the three resistors connected in parallel. The formula for calculating the equivalent resistance of two resistors in parallel is:

R_eq = (R_1 * R_2) / (R_1 + R_2)

Using this formula, we can calculate the equivalent resistance for the first two resistors:

R_eq_1_2 = (2Ω * 2Ω) / (2Ω + 2Ω) = 4Ω / 4Ω = 1Ω

Now, we can calculate the equivalent resistance of the third resistor (R_eq_1_2) in parallel with the third resistor (2Ω):

R_total = (1Ω * 2Ω) / (1Ω + 2Ω) = 2Ω / 3Ω = 0.67Ω (rounded to two decimal places)

Therefore, the total e.m.f of the three cells connected in parallel is 6V, and the total internal resistance is approximately 0.67Ω.

Frequently Asked Questions

Examkits is a JAMB CBT practice platform that provides over 20 years of past questions, Post UTME questions, and detailed video solutions to help students prepare for their exams.

You can practice JAMB past questions online, on Android, or on a desktop using the Examkits app. Just register on our website and choose your preferred device.

Yes. Our Android and Windows versions support offline usage. Once downloaded and activated, no internet is required to use most of the features.

Yes, Examkits provides detailed video explanations for all JAMB past questions from 2000 to 2024, helping students understand how to solve each problem.

Examkits offers free practice for some subjects. However, full access requires a one-time affordable activation fee for each version of the app.