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?

Answers were Sorted based on User's Feedback



power is the product of voltage and current.so we can measure the value of power just by using amm..

Answer / gajanan

apperent power = voltage X current,
we can calculate apperent power by ammeter and voltmeter
reading but
real power = voltage X current X power factor

to measure real power we need wattmeter

Is This Answer Correct ?    24 Yes 1 No

power is the product of voltage and current.so we can measure the value of power just by using amm..

Answer / nageshwaran.n

No doubt, we could use Voltmeter & Ammeter for calculating
Power but only Apparent Power that too at that instant.
Apparent power = voltage X current,

Actual RMS Power (real power) = voltage X current X power
factor

And to measure real power we need Wattmeter only.

Is This Answer Correct ?    11 Yes 0 No

power is the product of voltage and current.so we can measure the value of power just by using amm..

Answer / smita

RIGHT POWER IS VOLTAGE X CURRENT BUT FROM THIS WE GET ONLY
APPERENT POWER,AND WE REQIRE REAL POWER I.E VOLTAGE X
CURRENT X POWE3R FACTOR AND FOR THAT WE REQUIRE WATTMETER

Is This Answer Correct ?    6 Yes 0 No

power is the product of voltage and current.so we can measure the value of power just by using amm..

Answer / pillay

Yes as all have already said you dont need to use a watt meter
only if the circuit uses a Direct Current voltage and you can
calculate the power mentally by just looking at the voltmeter and ammeter.

Is This Answer Correct ?    1 Yes 0 No

power is the product of voltage and current.so we can measure the value of power just by using amm..

Answer / sudheer

if we use more no of meters error is more

Is This Answer Correct ?    0 Yes 0 No

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