Final answer:
The current I, in amperes, is calculated by dividing the charge Q in coulombs by the time t in seconds the charge takes to move. For a specific value of 0.21µC charge moving in L ms, time must be specified to calculate the exact current.
Step-by-step explanation:
The current when a static charge moves from one point to another can be calculated by using the formula I = Q/t, where I is the current in amperes, Q is the charge in coulombs, and t is the time in seconds it takes for the charge to move. In this case, if a charge of 0.21µC (which is 0.21 x 10⁻¶ C) moves in time L ms (where L is not specified but would be in milliseconds), we convert L ms to seconds by multiplying by 10⁻³. Therefore, the current I is equal to (0.21 x 10⁻¶ C) / (L x 10⁻³ s), assuming L gives the time in milliseconds.
However, the time period 'L' must be specified to provide an exact numerical answer for the current in amperes. For example, if L was 1 ms, the current would be I = 0.21 x 10⁻¶ C / 1 x 10⁻³ s = 0.21 x 10⁻³ A = 0.21 mA. This illustrates the process to find the current, but without a specific value for 'L', the actual current cannot be calculated.