power is the product of voltage and current.so we can measure the value of power just by using ammeter and voltmeter.......then why do we use a wattmeter?

5 Answers  

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AC is the magnitude of sinosudial-wave but we use cose value to determine power factor instead of sine value.

2 Answers  

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What the difference between three phase contactor (coil 110vac) & three phase SSR (control voltage 110Vac)? May I use contactor in place of SSR?

0 Answers  

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Is 3C x 2.5 Sqmm Cable can withstand 40Amp Starting current? If Yes then specify your ans.

2 Answers   NTPC,

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How size of Earth Strip is determined for a particular Fault current.

1 Answers  

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How to design pavement quality concrete by using C.R.C.P Method

0 Answers   L&T,

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What are the common sources of energy?

0 Answers  

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How can you calculate the size of the down conductor cable for the lightning protection system. Is 70mm2 cable can replace 95mm 2 bare copper cable when the copper tape size is 25Wx3 thk mm.

0 Answers  

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What is the amount of no load current of 630 kVA tranformer voltage ratio 11kV/440V ?

13 Answers  

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How can we choose the rating of submersible motors

0 Answers  

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The power factor of the fixed load is 0.8, now the p.f is varying from 0.8 to 0.5.

0 Answers  

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What are types of encoders?

19 Answers   ITC Infotech, UFO, Wipro,

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