State any two disadvantages of one wattmeter method of measurement of 3 phase power.

State any two disadvantages of one wattmeter method of measurement of 3 phase power.
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Answer :

State any two disadvantages of one wattmeter method of measurement of 3 phase power.

Disadvantages of one wattmeter method:- 1. Only used for balanced load 2. It can not be used for unbalanced load 3. It is used for star connection then neutral point must be available 4. Delta connection must be opened to connect current coil.

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