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Find the ratio ofcurrents as measured by...

Find the ratio ofcurrents as measured by ammeter in two cases when the key is open and when the key is closed :

A

`9//8`

B

`10//11`

C

`8//9`

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
C
When `K` is open
`R_("net")=3R//2`
`:. i_1=E//(3R//2)=(2E)/(3R)`
When K is closed
`R_("net")=2[(Rxx2R)/(R+2R)]=4/3R`
`:. i_2=E//(4R//3)=(3E)/(4R)`
`:. i_1/i_2=8/9`
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