In the given circuit the internal resistance of the 18 V cell is negligible. If R1 = 400 Ω , R3 = 100 Ω and R4 = 500 Ω and the reading of an ideal voltmeter across R4 is 5V, then the value R2 will be :

Question

In the given circuit the internal resistance of the 18 V cell is negligible. If R1 = 400 Ω , R3 = 100 Ω and R4 = 500 Ω and the reading of an ideal voltmeter across R4 is 5V, then the value R2 will be : (A) 300 Ω  (B) 230 Ω  (C) 450 Ω  (D) 550 Ω

Tardigrade Admin · Accepted Answer

V4 = 5V i1 = (V4/R4) = 0.01 A V3 = i1 R3 = 1V V3 +V4 = 6V = V2 V1 + V3 + V4 = 18 V V1 = 12V i = (V1 /R1) = 0.03 Amp . i2 = 0.02 Amp V2 = 6V R2 = (V2 /i2) = (6/0.02) = 300 Ω

Q. In the given circuit the internal resistance of the $18 V$ cell is negligible. If $R_{1} = 400 Ω, R_{3} = 100Ω$ and $R_{4} = 500 Ω$ and the reading of an ideal voltmeter across $R_{4}$ is $5 V$ , then the value $R_{2}$ will be :

$300 Ω$

$230 Ω$

$450 Ω$

$550 Ω$

$V_{4} = 5 V$
$i_{1} = \frac{V _{4}}{R _{4}} = 0.01 A$
$V_{3} = i_{1} R_{3} = 1 V$
$V_{3} + V_{4} = 6 V = V_{2}$
$V_{1} + V_{3} + V_{4} = 18 V$
$V_{1} = 12 V$
$i = \frac{V _{1}}{R _{1}} = 0.03 A m p .$
$i_{2} = 0.02 A m p V_{2} = 6 V$
$R_{2} = \frac{V _{2}}{i _{2}} = \frac{6}{0.02} = 300Ω$

Q. In the given circuit the internal resistance of the 18V cell is negligible. If R1​=400Ω,R3​=100Ω and R4​=500Ω and the reading of an ideal voltmeter across R4​ is 5V, then the value R2​ will be :

300Ω

230Ω

450Ω

550Ω