Question

if the voltage across a fixed value of resistance is increased five times, what will be the variation in current?

Answer 1

Hi,

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This prob is simple......

you might already know the formula [ V = R I ]

V = potential/voltage

I = Current

R = resistance {proportionality const. b/w V and I}

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For these kind of problems where a term is varied wrt. another....

take ratio of proportionalities...

like so...

(initial values) : v , i , r  [all small letters]

(final values) : V , I , R [Capital letters]

now:

V/v = I/i x R/r {note here} just dividing both proportionalities

and we know ,.... V = 5 v and R = r

we get ;

I {final current} = 5 i {initial current}

final current is five times the initial value;

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Ps. Enjoy ;)