A DC source of 30 V is connected across two resistors of 200 Ω each connected in series. A voltmeter of resistance 200 Ω is connected across a resistor. It reads

Question

A DC source of 30 V is connected across two resistors of 200 Ω each connected in series. A voltmeter of resistance 200 Ω is connected across a resistor. It reads (A) 20 V (B) 30 V (C) 10 V (D) 5 V

Tardigrade Admin · Accepted Answer

Given situation is shown in the figure
Net resistance of the circuit

R = 200 + \frac{200 \times 200}{200 + 200}

= 300Ω

Current drawn from battery,

I = \frac{V}{R} = \frac{30}{300} = 0.1 A

I_{1} = \frac{200 \times I}{200 + 200} = \frac{I}{2},

or,

I_{2} = \frac{l}{2}

Reading of voltmeter

= I_{1} R = (\frac{0.1}{2}) \times 200 = 10 V

Q. A DC source of 30V is connected across two resistors of 200Ω each connected in series. A voltmeter of resistance 200Ω is connected across a resistor. It reads

20 V

30 V

10 V

5 V

Given situation is shown in the figure Net resistance of the circuit R=200+200+200200×200​ =300Ω Current drawn from battery, I=RV​=30030​=0.1A I1​=200+200200×I​=2I​, or, I2​=2l​ Reading of voltmeter =I1​R=(20.1​)×200=10V

Q. A DC source of $30 V$ is connected across two resistors of $200 Ω$ each connected in series. A voltmeter of resistance $200 Ω$ is connected across a resistor. It reads