Question

In a test on a bakelite sample at 20 kV, 50 Hz by Schering bridge shown in below figure. Then the values of $C_x,R_x$ respectively are

• A. 327 pF, 259 $k\Omega$
• B. 259 pF, 327 $k\Omega$
  
• C. 429 pF, 259 $k\Omega$
• D. 259 pF, 429 $k\Omega$

Answer 1

The correct option is D 259 pF, 429 $k\Omega$

$C_s=\frac{R_4}{R_3}{C}_2$

$=\frac{318}{130}\times 106\times {10}^{-12}=259.29pF$

$R_x=R_3\times \frac{C_4}{C_2}$

$=130\times \frac{0.35\times {10}^{-6}}{106\times {10}^{-12}}=429.25k\Omega$