The amount of work done in moving a charge of 4C across two points having a potential difference of 6V is ______.

24 J

The correct answer is option 4. 24 J.

The amount of work done in moving a charge across a potential difference is given by the formula:

\[ \text{Work} = \text{Charge} \times \text{Potential difference} \]

Given that the charge \( Q = 4 \, \text{C} \) and the potential difference \( V = 6 \, \text{V} \), we can use the formula to find the work done:

\[ \text{Work} = Q \times V = 4 \, \text{C} \times 6 \, \text{V} = 24 \, \text{J} \]

Therefore, the amount of work done in moving a charge of 4 C across two points having a potential difference of 6 V is \( 24 \, \text{J} \).

So, the correct answer is: \( 24 \, \text{J} \)