Practice portal › Current Electricity › Electric Current and Drift Velocity

The current density in a cylindrical wire of radius r=4.0 mm is 1.0×10⁶ A/m². The current through the outer portion of the wire between radial distance r/2 and r is xπ A; where x is ______.

Asked in JEE Main 27th June 2nd Shift 2022 · Drift velocity, mobility and current density

Answer: 12

Step-by-step solution

Uniform J: current through the annulus is J times its area.

Area =π(r²-(r²)/4)=3/4π r²=3/4π×16×10⁻⁶ m²=12π×10⁻⁶ m².

I=1.0×10⁶×12π×10⁻⁶=12π A.

So x=12.

More Electric Current and Drift Velocity questionsAll Electric Current and Drift Velocity questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer