Question

The reading of the ammeter and voltmeter in the following circuit respectively are

• A. 2 A, 200 V
• B. 1.5 A, 100 V
• C. 2.7 A, 220 V
• D. 2.2 A, 220 V

Answer 1

The correct option is A

2 A, 200 V

Ammeter and Voltmeter.

1. Ammeter- It is a device used to measure the current flowing in the circuit.
2. Voltmeter- It is a device used to measure the potential difference between two points of a circuit.

Step 1:Given:

Frequency = 50Hz

Total voltage in the circuit, $V_{Total}=200V$

The instantaneous voltage across the inductor,$V_L=200V$

The instantaneous voltage across the capacitor, $V_C=200V$

Resistance of resistor, $R=100\Omega$

Step 2: Formula Used:

$\begin{array}{l}{V}_{total}=\sqrt{(V_L-V_C{)}^2+V_R^2}\end{array}$

where $V_{Total}$ is total voltage of circuit, $V_L$ is Voltage across inductor, $V_C$ is voltage across capacitor, and $V_R$ is voltage across resistor.

Step 3: Calculating reading of voltmeter

$V_R$ is the reading of voltmeter.

$$\begin{gathered} \begin{array}{l}{V}_{total}=\sqrt{(V_L-V_C{)}^2+V_R^2}\end{array} \\ \begin{array}{l}200=\sqrt{(200-200{)}^2+V_R^2}\end{array} \\ {V}_R=200V \end{gathered}$$

Step 4: Calculating readings of ammeter

$I$ is the reading of ammeter.

$$\begin{gathered} I=\frac{V_R}{R} \\ I=\frac{200}{100} \\ I=2A \end{gathered}$$

Hence reading in voltmeter is 200V and reading in ammeter is 2A. So option A is correct.