The full scale deflection current of a galvanometer of resistance `1Omega` is `5 mA`. How will you convert it into a voltmeter of range of `V`?

Explanation

To convert a galvanometer into a voltmeter, we need to connect a resistor in series with the galvanometer. Here’s the step-by-step solution to find the value of the resistor needed for a voltmeter with a range of 5 volts.

### Step-by-Step Solution:

1. **Understand the Given Values**:
- Resistance of the galvanometer, \( R_g = 1 \, \Omega \)
- Full-scale deflection current of the galvanometer, \( I_g = 5 \, \text{mA} = 5 \times 10^{-3} \, A \)
- Desired voltage range of the voltmeter, \( V = 5 \, V \)

2. **Use the Formula for Voltage**:
The voltage across the galvanometer when it is connected in series with a resistor \( R \) can be expressed as:
\[ V = I_g \times (R_g + R) \]
where \( V \) is the total voltage across the circuit.

3. **Substituting Known Values**:
Substitute the known values into the formula:
\[ 5 = 5 \times 10^{-3} \times (1 + R) \]

4. **Rearranging the Equation**:
To isolate \( R \), first divide both sides by \( 5 \times 10^{-3} \):
\[ \frac{5}{5 \times 10^{-3}} = 1 + R \]
Simplifying the left side:
\[ 1000 = 1 + R \]

5. **Solving for R**:
Now, subtract 1 from both sides:
\[ R = 1000 - 1 = 999 \, \Omega \]

### Final Result:
The value of the resistor \( R \) needed to convert the galvanometer into a voltmeter with a range of 5 volts is \( R = 999 \, \Omega \).