Question

The Value in M ohms of a resistor required to discharge a 30 Mfd capacitor to safe levels, in the time required by the NYC electrical Code, that has been energized to 650V is most nearly?

Answer 1

To calculate the value of the resistor required to discharge a capacitor, use the formula for the time constant (τ) of a RC circuit, which is given as τ = RC, where R is the resistance and C is the capacitance.

Step-by-step explanation:

To calculate the value of the resistor required to discharge a capacitor, we can use the formula for the time constant (τ) of a RC circuit, which is given as τ = RC, where R is the resistance and C is the capacitance.

In this case, the capacitor has a capacitance of 30 microfarads (Mfd) and it needs to be discharged to safe levels within the time required by the NYC electrical code. The voltage of the capacitor is 650V.

To determine the resistance (R), we can rearrange the formula as R = τ / C and substitute the values of τ and C.

Let's calculate the time constant first. The time constant can be determined using the formula τ = RC, where C is the capacitance and R is the resistance. In this case, the capacitance is 30 Mfd and the resistance is unknown. Let's calculate τ.

τ = 30 Mfd * R

Now, we can substitute the values of τ and C into the formula to calculate the resistance:

R = τ / C