To solve the problem, we need to identify what physical quantity is measured in kilowatt-hours.
1. Understanding Kilowatt-Hour:
A kilowatt-hour (kWh) is a unit of energy commonly used to measure electrical energy consumption. It represents the amount of energy used when 1 kilowatt (1000 watts) of power is used for 1 hour.
2. Relation to Energy:
Since power × time = energy:
\( \text{Energy} = \text{Power} \times \text{Time} \)
A kilowatt-hour is a derived unit of energy.
3. SI Unit Equivalence:
1 kWh = \( 1000 \times 3600 \) joules = 3.6 × 106 joules
4. Elimination of Other Options:
- Potential difference is measured in volts (V)
- Current is measured in amperes (A)
- Electrical resistance is measured in ohms (Ω)
Final Answer:
The kilowatt-hour is the unit of Electrical energy.
The maximum percentage error in the equivalent resistance of two parallel connected resistors of 100 \( \Omega \) and 900 \( \Omega \), with each having a maximum 5% error, is: \[ {(round off to nearest integer value).} \]
The induced emf in a 3.3 kV, 4-pole, 3-phase star-connected synchronous motor is considered to be equal and in phase with the terminal voltage under no-load condition. On application of a mechanical load, the induced emf phasor is deflected by an angle of \( 2^\circ \) mechanical with respect to the terminal voltage phasor. If the synchronous reactance is \( 2 \, \Omega \), and stator resistance is negligible, then the motor armature current magnitude, in amperes, during loaded condition is closest to: \[ {(round off to two decimal places).} \]
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An ideal low pass filter has frequency response given by
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