Schering bridge

Q. The four arms of a bridge are:
arm ab : an imperfect capacitor $C_1$ with an equivalent series resistance of $r_1$
arm bc : a non-inductive resistance $R_3$
arm cd : a non-inductive resistance $R_4$
arm da : an imperfect capacitor $C_2$ with an equivalent resistance of $r_2$ in series with $R_2$.

A supply of 450 Hz is given between terminal a and c and the detector is connected between b and d. At balance

$R_2=4.8\Omega R_3=2000\Omega R_4=2850\Omega$
and $C_2=0.5\mu F$ and $r_2=0.4\Omega$



The dissipating factor of capacitor $C_1$ is ______ $\times {10}^{-3}$.

1. 7.34

Q. 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

1. 327 pF, 259 $k\Omega$
2. 259 pF, 327 $k\Omega$
   
3. 429 pF, 259 $k\Omega$
4. 259 pF, 429 $k\Omega$

Q. The equations under balanced conditions for a bridge are:

$R_1=\frac{R_2{R}_3}{R_4}and{L}_1=R_2{R}_3{C}_{4}where{R}_{1}and{L}_1$ are respectively unknown resistance and inductance. In order to achieve faster balance which of the following variables are chosen?

1. $R_{2}and{R}_3$
2. $R_{2}and{C}_4$
3. $R_{4}and{C}_4$
4. $R_{3}and{C}_4$

Q. If the ac bridge circuit shown below is balanced, the element Z can be a

1. pure capacitor
2. pure inductor
3. R-L series combination
4. R-L parallel combination