Mark out the correct options.

Options

A. An ammeter should have small resistance.
B. An ammeter should have large resistance.
C. A voltmeter should have small resistance.
D. A voltmeter should have large resistance.

Answer

To solve the question, we need to analyze the four options provided regarding the characteristics of ammeters and voltmeters in electrical circuits.

### Step-by-Step Solution:

1. **Understanding the Ammeter**:
- An ammeter is used to measure the current flowing through a circuit.
- It must be connected in series with the circuit element whose current we want to measure.

2. **Resistance of the Ammeter**:
- For an ammeter to accurately measure the current, it should have a **small resistance**.
- If the ammeter has a high resistance, it will affect the total resistance of the circuit and change the current flowing through it, leading to inaccurate measurements.

3. **Understanding the Voltmeter**:
- A voltmeter measures the potential difference (voltage) across two points in a circuit.
- It is connected in parallel with the component across which the voltage is to be measured.

4. **Resistance of the Voltmeter**:
- A voltmeter should have a **large resistance**.
- This is to ensure that it does not draw significant current from the circuit, which would alter the voltage across the component being measured.
- If the voltmeter has a low resistance, it can act as a load and draw current, affecting the voltage reading.

5. **Evaluating the Options**:
- **Option 1**: "The ammeter should have small resistance." - **Correct**
- **Option 2**: "The ammeter should have large resistance." - **Incorrect**
- **Option 3**: "A voltmeter should have small resistance." - **Incorrect**
- **Option 4**: "A voltmeter should have large resistance." - **Correct**

### Conclusion:
The correct options are **Option 1** and **Option 4**.