Request a call back

f r of a wire is increased by 50 and potential difference decreased by 50% then find the percentage change in current
Asked by imayushanand223 | 29 Dec, 2021, 08:49: AM Expert Answer
Resistance of wire , R = ρ × ( L / A)  = ρ × [ L / ( π r2 ) ]

where ρ is resistivity of material , L is length of wire , A is area of crs section and r is radius of wire

hence, resistance of wire is iversly proportional to quare of radus.

R = C / r2

where C is constant if material of wire and length of wire are fixed .

If radius is increased by 50%  , then new radius r' = 1.5r

New resistance = R '  = C / (1.5 r )2  = ( 4 / 9 ) R

If voltage is decreased by 50% , then current with new resistance R ' is determined as

I '  = [ (1/2) V ] / [ ( 4 / 9) R ]  = ( 9 / 8 ) ( V / R ) = 1.125 I

where I is current with initial voltage V and initial radius of wire r .

Hence we see that current increases by 12.5 %
Answered by Thiyagarajan K | 29 Dec, 2021, 10:25: AM
CBSE 11-science - Physics
if the momentum of body decreases by 30% its kinetic energy decreased by Asked by bhargavchary19 | 23 Dec, 2022, 07:33: AM ANSWERED BY EXPERT
CBSE 11-science - Physics ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by kdimple765 | 09 Jun, 2022, 05:07: PM ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by rajveermundel7 | 18 May, 2022, 09:01: PM ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by duritanaik | 03 May, 2022, 08:59: AM ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by imayushanand223 | 29 Dec, 2021, 08:49: AM ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by vithalsawant119 | 24 Nov, 2021, 09:06: PM ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by anupchan2005 | 03 Sep, 2021, 10:20: PM ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by bamanetushar48 | 29 May, 2021, 02:16: PM ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by aartiingole27 | 31 Mar, 2021, 02:26: PM ANSWERED BY EXPERT