5) In the circuit shown, cells are of equal emf E but of different internal resistance r1=6Ω and r2=4Ω - Physics - Current Electricity

Question

5) In the circuit shown, cells are of equal emf E but of different
internal resistance r 1 = 6 Ω   a n d   r 2 = 4
Ω Reading of the ideal voltmeter connected across cell 1 is
zero Value of the external resistance R in ohm is equal to

( A )     2 ( B )   2 4 ( C )   10 ( D )  
24

Sanjay Singh · Accepted Answer

Dear student
Applying kirchoffs loop rule in the given loop-2E+i×(r1+r2+R)=02E=i×(r1+r2+R)i=2E(r1+r2+R)
1As the voltage drop across the ideal voltmeter is zeroV+-V-=0E-i×r1=0i=Er1
2From eqn 1 and 
22E(r1+r2+R)=Er12r1=r1+r2+Rr1-r2=RR=6-4=2ΩRegards

5) In the circuit shown, cells are of equal emf E but of different internal resistance r 1 = 6 Ω a n d r 2 = 4 Ω . Reading of the ideal voltmeter connected across cell 1 is zero. Value of the external resistance R in ohm is equal to. ( A ) 2 ( B ) 2 . 4 ( C ) 10 ( D ) 24

5) In the circuit shown, cells are of equal emf E but of different internal resistance $r_{1} = 6 Ω a n d r_{2} = 4 Ω .$ Reading of the ideal voltmeter connected across cell 1 is zero. Value of the external resistance R in ohm is equal to.

$(A) 2 (B) 2.4 (C) 10 (D) 24$