Question

The Wheatstone bridge shown in Fig. here, getsbalanced when the carbon resistor used as R1has the colour code ( Orange, Red, Brown).The resistors R2 and R4 are 80 and 40respectively.Assuming that the colour code for the carbonresistors gives their accurate values, the colour codefor the carbon resistor, used as R3, would be

• A. Red, Green, Brown
• B. Brown, Blue, Brown
• C. Grey, Black, Brown
• D. Brown, Blue, Black

Answer 1

Answer: (B)

Brown, Blue, Brown

R1 = 32 10 = 320
for wheat stone bridge
$⟹\frac{R_1}{R_3}=\frac{R_2}{R_4}$
$\frac{320}{R_3}=\frac{80}{40}$
$R_3=160$