An ammeter has a resistance of `50Omega` and a full scale deflection current `50muA`. It can be used as a voltmeter or as a higher range ammeter provided that a resistance is added to it. Which of the following is/are true?

Options

A. 10 V range with approximately `200kOmega` resistance in series
B. 30 V range with approximately `200kOmega` resistance in series
C. 1 mA range with `50Omega` resistance in parallel
D. 0.1 mA range with `50Omega` resistance in parallel

Answer

To solve the problem, we need to analyze the given information about the ammeter (or galvanometer) and determine its usage as a voltmeter and a higher range ammeter.

### Step-by-Step Solution:

1. **Identify Given Values**:
- Resistance of the ammeter (R_g) = 50 Ω
- Full scale deflection current (I_g) = 50 μA = 50 × 10^(-6) A

2. **Convert the Ammeter to a Voltmeter**:
- When converting an ammeter to a voltmeter, we need to add a resistance (R) in series.
- The total voltage (V) across the voltmeter can be calculated using Ohm's law:
\[ V = I_g \times (R_g + R) \]
- If we assume R = 200 kΩ = 200 × 10^3 Ω, then:
\[ V = 50 \times 10^{-6} \times (50 + 200 \times 10^3) \]
- Calculate:
\[ V = 50 \times 10^{-6} \times (50 + 200000) = 50 \times 10^{-6} \times 200050 \]
- Neglecting the 50 in comparison to 200000:
\[ V \approx 50 \times 10^{-6} \times 200000 = 10 \text{ volts} \]

3. **Convert the Ammeter to a Higher Range Ammeter**:
- To convert the ammeter to a higher range ammeter, we add a resistance (R_s) in parallel.
- The total current (I) through the ammeter can be expressed as:
\[ I = \frac{I_g \times (R_g + R_s)}{R_s} \]
- Setting R_s = 50 Ω:
\[ I = \frac{50 \times 10^{-6} \times (50 + 50)}{50} \]
- Simplifying:
\[ I = \frac{50 \times 10^{-6} \times 100}{50} = 100 \times 10^{-6} = 0.1 \text{ mA} \]

4. **Conclusion**:
- The range of the voltmeter is approximately 10 volts.
- The range of the higher range ammeter is 0.1 mA.

### Final Answers:
- The statements regarding the voltmeter range being 10 volts and the ammeter range being 0.1 mA are true.