In an electrical circuit containing a source of emf and a load resistance, the voltmeter is connected by mistake in series with the load across the source and ammeter is connected parallel to the load. Then which meter burns out

Options

A. ammeter
B. voltmeter
C. both ammeter and voltmeter
D. neither ammeter nor voltmeter

Answer

To solve the problem of which meter will burn out when a voltmeter is mistakenly connected in series with a load resistance and an ammeter is connected in parallel to the load, we can analyze the situation step by step.

### Step-by-Step Solution:

1. **Understanding the Circuit Configuration**:
- The circuit consists of a source of electromotive force (emf) and a load resistance.
- The voltmeter is incorrectly connected in series with the load resistance.
- The ammeter is connected in parallel to the load resistance.

2. **Identifying the Role of Each Meter**:
- A voltmeter is designed to measure the voltage across two points and should be connected in parallel with the load.
- An ammeter is designed to measure the current flowing through a circuit and should be connected in series with the load.

3. **Analyzing the Resistance of the Meters**:
- The resistance of an ideal voltmeter is very high (approaching infinity), which means it does not allow significant current to flow through it.
- The resistance of an ammeter is very low, designed to allow maximum current to flow through it without affecting the circuit.

4. **Current Flow in the Circuit**:
- Since the voltmeter is in series, it will limit the current flowing through the circuit due to its high resistance.
- The ammeter, being in parallel with the load, will create a path of low resistance for the current to flow.

5. **Determining Current Distribution**:
- The current from the source will primarily flow through the ammeter because it has a much lower resistance compared to the voltmeter.
- Since the voltmeter is in series and has a very high resistance, it will not allow significant current to flow through it.

6. **Conclusion on Meter Damage**:
- Because the ammeter is in parallel with the load and has low resistance, it will carry the majority of the current.
- However, since the voltmeter is in series with a high resistance, it will not allow current to flow through it, leading to an open circuit condition.
- In this configuration, neither the ammeter nor the voltmeter will burn out because the current is effectively limited by the high resistance of the voltmeter.

### Final Answer:
**Neither the ammeter nor the voltmeter will burn out.**