Step 1: Use the formula for capacitance of a parallel plate capacitor
The capacitance \( C \) of a parallel plate capacitor is given by:
\[
C = \epsilon_0 \frac{A}{d}
\]
where:
- \( \epsilon_0 \) is the permittivity of free space,
- \( A \) is the area of the plates,
- \( d \) is the distance between the plates.
Step 2: Understand the effect of halving the distance
Since the capacitance is inversely proportional to the distance between the plates, halving the distance \( d \) will double the capacitance.
Step 3: Calculate the new capacitance
Given the initial capacitance is \( 10 \, \mu\text{F} \), when the distance between the plates is halved, the new capacitance will be:
\[
C_{\text{new}} = 2 \times 10 \, \mu\text{F} = 20 \, \mu\text{F}
\]
Answer: Therefore, the new capacitance is \( 20 \, \mu\text{F} \). So, the correct answer is option (1).