Get Answers to all your Questions

header-bg qa

In a wire of cross-section radius r, free electrons travel with drift velocity v when current I flows through the wire. What is the current in another wire of quarter the radius and of the same material when drift velocity is 8V.

Option: 1

2I


Option: 2

\frac{I}{3}


Option: 3

\frac{I}{2}


Option: 4

3I


Answers (1)

best_answer

I = neAV_d

\frac{I_1}{I_2}=\frac{A_1(v_d)_1}{A_2(v_d)_2}

\frac{I_1}{I_2}=\frac{\pi r^2}{\pi \left (\frac{r}{4} \right )^2}\times \frac{V}{8V}

I_2=\frac{I}{2}

Posted by

manish

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE