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Assertion : Kilovol-ampere (kVA) and kil...

Assertion : Kilovol-ampere (kVA) and kilowatt-hour have the same dimensions.
Reason : Both are the units of energy.

A

If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

B

If both Assertion and Reason are true and Reason is not correct explanation of Assertion.

C

If Assertion is true but Reason is false.

D

If both Assertion and Reason are false.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze the assertion and the reason provided. ### Step 1: Understand the Assertion The assertion states that "Kilovolt-ampere (kVA) and kilowatt-hour (kWh) have the same dimensions." - **Kilovolt-ampere (kVA)** is a unit of apparent power in an electrical circuit. - The dimensions of power can be expressed as: \[ \text{Power (P)} = \text{Voltage (V)} \times \text{Current (I)} \] The unit of power is Volt-Ampere (VA), and thus: \[ \text{Dimensions of kVA} = [M^1 L^2 T^{-3}] \text{ (since V = M L^2 T^{-3} I^{-1})} \] ### Step 2: Understand the Reason The reason states that "Both are the units of energy." - **Kilowatt-hour (kWh)** is a unit of energy. It is defined as the amount of energy consumed when a power of one kilowatt is used for one hour. - The dimensions of energy can be expressed as: \[ \text{Energy (E)} = \text{Power (P)} \times \text{Time (t)} \] Since the unit of power is kilowatt (kW), and time is in hours (h), the dimensions of energy become: \[ \text{Dimensions of kWh} = [M^1 L^2 T^{-2}] \text{ (since kW = M L^2 T^{-3})} \] ### Step 3: Compare Dimensions Now, we compare the dimensions of kVA and kWh: - Dimensions of kVA: \([M^1 L^2 T^{-3}]\) - Dimensions of kWh: \([M^1 L^2 T^{-2}]\) Since the dimensions are not the same, the assertion is **false**. ### Step 4: Evaluate the Reason The reason states that both units are units of energy. Since kVA is a unit of power and kWh is a unit of energy, this statement is also **false**. ### Conclusion Both the assertion and the reason are false. Therefore, the correct answer is that both the assertion and the reason are false. ### Final Answer Both assertion and reason are false. ---
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