Question

In the circuit shown in the figure $V_{1}and{V}_2$ are two voltmeters of resistance 3000$\Omega$ and 2000$\Omega$ respectively $R_1=2000\Omega ,R_2=3000\Omega andE=200V$. A is an ideal ammeter consider both cases i.e. switch S open or switch S closed to match the readings. The cell is ideal Ammeter $\left(A_1\right)and\left(A_2\right)$ are also ideal.

• A. Reading of voltmeter $V_1$ in volt may be 120 Volt
• B. Reading of voltmeter $V_1$ in volt may be 100 Volt
• C. Reading of ammeter A may be 100 miliampere
• D. Reading of ammeter $A_1$ may be 50 miliampere

Answer 1

Answer: (A), (B), (D)

The correct options are
A Reading of voltmeter $V_1$ in volt may be 120 Volt
B Reading of voltmeter $V_1$ in volt may be 100 Volt
D Reading of ammeter $A_1$ may be 50 miliampere

When S=closed

$R_{AB}=3000\parallel 2000R_{BC}=2000\parallel 3000$

Since $R_{AB}=R_{BC}$

then$V_{AB}=V_1=\frac{E}{2}=100V$

$I_1=$ reading of $A_1=\frac{100}{2000}=50mA$

When $S⟶Open$

$V_1=\frac{R_1}{R_1+R_2}\left(E\right)$

$=\frac{3000}{5000}\times 200=120V$