- #1

vkash

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## Homework Statement

A ammeter and a voltmeter are joined in series to a cell . Their reading are A and V respectively. If a resistance is now joined in parallel with voltmeter,

(a) Both A and V will increase

(b) Both A and V will decrease

(c) A will decrease V will increase

(d) A will increase V will decrease

## Homework Equations

You know that so i needn't to provide

## The Attempt at a Solution

For me option 'B' is correct

why?

because; in first case net resistance in R

_{v}+R

_{a}so current in the circuit is [tex]\frac{V}{R

_{v}+R

_{a}}[\tex] In second case a new resistance is introduced in the circuit so net resistance is R

_{v}+R

_{a}+

**R**. Current in this case is [itex]\frac{V}{R

_{v}+R

_{a}+

**R**}[\itex]. A we can see quit clearly that [itex]\frac{V}{R

_{v}+R

_{a[/sub}[\itex] > [itex]\frac{V}{Rv+Ra+R}[/itex] so current in second case (say I2) is greater than current in first case(say I1) Potential difference between the voltmeter in first case is [itex]RvI1[\itex] and in second case is [itex]RvI2[\itex]. I2<i1 so potential difference between the voltmeter in first case should greater than that in second case. so what's the conclusion; that is ammeter reading as well as voltmeter reading will drop so. Option B is correct for me. As always i ask. where am i wrong? sorry friends i tried to change / \ and some others, but none work with tex itex so try understand as it is written or just put answer.}

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