Correct option is B
Definitions
Normal System Voltage: This is the standard operating voltage for which the system is designed.
Short Circuit Current: This is the maximum current that can flow when a short circuit occurs; it is a high magnitude current that flows when the electrical circuit is closed, bypassing the normal load.
Relevant Options:
(a) Short Circuit Power
This typically refers to the total power available or released during a short circuit condition.
It can be calculated by the product of the voltage and the short circuit current.
(b) Short Circuit KVA
This is a specific measurement of the power in kilovolt-amperes during a short circuit.
It is essentially the same as short circuit power but typically expressed in KVA units, which is a direct function of voltage and current without taking into account the power factor (since it assumes a power factor of 1).
Incorrect Options:
(c) Open Circuit KVA and (d) Open Circuit Power
These terms relate to conditions where the circuit is open, i.e., no current flows.
These terms are irrelevant to a scenario where a short circuit (a closed-circuit condition) is being considered.
Conclusion:
The most appropriate answer for the product of the system's normal operating voltage and the maximum current during a fault (short circuit current) is (b) Short Circuit KVA
This term correctly refers to the power capability under fault conditions in terms of KVA, which is a common way to express such values in power system engineering.
Detailed Explanation:
Voltage × Current = Power: The basic formula for electrical power (P = VI) is applicable here. In the context of a short circuit, where the power factor is generally close to unity (especially in purely resistive circuits or theoretical discussions), the product of voltage and current gives the apparent power in KVA.
Why KVA: - Power in electrical systems, particularly in contexts involving faults, is often discussed in terms of KVA to simplify calculations by omitting the power factor, which may not be precisely known during fault conditions or may be close to one.
Thus, the answer (b) Short Circuit KVA correctly represents the power condition during a short circuit, indicating the total apparent power available or potentially released during such an event.
