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The resistance of hot tungsten filament ...

The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use?

A

`400Omega`

B

`200Omega`

C

`40Omega`

D

`20Omega`

Text Solution

Verified by Experts

`R_(H)=10R_(H)`
`R=(V^(2))/(P)=(200xx200)/(100)=400Omega`
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