CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

When a current of $$2A$$ flows in a battery from negative to positive terminal, the potential difference across it is $$12V$$. If a current of $$3A$$ flowing in the opposite direction produces a potential difference of $$15V$$, the EMF of the battery is


A
12.6V
loader
B
13.2V
loader
C
13.5V
loader
D
14V
loader

Solution

The correct option is B $$13.2V$$
Let the emf of cell $$=E$$
In 1st case : $$V_1=E-I_1r$$   where r= internal resistance of cell. 
or $$12=E-2r  ......(1)$$
In 2nd case as current in opposite direction so the equation becomes 
$$V_2=E+I_2r$$ or $$15=E+3r  ....(2)$$
using (1),  $$15=E+3(E/2-6)$$ or $$2.5 E=33 \Rightarrow E=13.2  V$$

Physics
NCERT
Standard XII

Suggest Corrections
thumbs-up
 
0


similar_icon
Similar questions
View More


similar_icon
Same exercise questions
View More


similar_icon
People also searched for
View More



footer-image