wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A current passes through a wire of nonuniform cross-section. Which of the following quantities is independent of the cross-section?

A
The charge crossing in a given time interval.
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
Drift speed
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Current density
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
None of these
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A The charge crossing in a given time interval.
Since,
Charge entering at one end of a conductor = charge leaving at the other end,

So current does not change with change in cross-section and conductor remains uncharged when current flows through it.

As the cross-sections are in series, so the current in them will be the same.

From current and drift velocity relation,

I=neAvd

Since, in this case current and n are constant

vd1/A.

At one cross-section is more, hence the drift velocity is less.

And current density J is given by

J=IA

J1A (I=constant)

So, current density depends upon area of cross-section.

Hence, option (a) is correct

flag
Suggest Corrections
thumbs-up
4
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon