0

Guest

Courses New

Two identical cells each of emf E and internal resistance r are connected in parallel with an external resistance R. To get maximum power developed across R, the value of R is (A) R = r/2 (B) R = r (C) R = r/3 (D) R = 2r

Two identical cells each of emf E and internal resistance r are connected in parallel with an external resistance R. To get maximum
power developed across R, the value of R is
(A) R = r/2 (B) R = r (C) R = r/3 (D) R = 2r

Grade:

2 Answers

Arun
25750 Points
3 years ago
Equivalent resistance Req​=2r​+R=2r+2R​
∴I=r+2R2E​
 
For maximum power consumption I should be maximum so denominator is minimum. For this
r+2R=(r​−2R​)2+2r​2R​
 
⇒r​−2R​=0
 
⇒R=2r​
Vikas TU
14149 Points
3 years ago
first of all You should know that parallel cells just increase the capacity of the cell(means life) but keeps the voltage same as of the single cell emf.
So for max. Power
P=E^2/4R (r=R)
Now for your question 2 cells have internal resistance of r and connected in parallel so equivalent internal resistance is r/2
So here is our answer
R=r/2.
 

Think You Can Provide A Better Answer ?

Other Related Questions on Engineering Entrance Exams

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More