99 Percentile Qs Bank for JEE MainPhysicsCurrent Electricity
A fuse wire of radius 0.2 ~mm blows off with a current of 5 ~A . The fuse wire of same material but of radius 0.3 ~mm will blow off with a current of
Options
- A15 2 ~A
- B5 3 2 ~A
- C5 27 8 ~A
- D5 A
Correct answer
C. 5 27 8 ~A
Step-by-step solution
If I= current rating of fuse wire and r= radius of fuse wire, then relation, I^2 r^3 aligned & I₂ I₁ = ( r₂ r₁ )^ 3 / 2 , given r₁=0.2 ~mm , I₁=5 ~A & r₂=0.3 ~mm , I₂=? & I₂=5 ( 0.3 0.2 )^ 3 / 2 =5 27 8 ~A aligned