JEE PYQ: Current Electricity Question 56
Question 56 - 2019 (09 Jan 2019 Shift 1)
Drift speed of electrons, when 1.5 A of current flows in a copper wire of cross section $5,\text{mm}^2$, is $v$. If the electron density in copper is $9 \times 10^{28}/\text{m}^3$ the value of $v$ in mm/s close to (Take charge of electron to be $= 1.6 \times 10^{-19}$ C)
(1) 0.02
(2) 3
(3) 2
(4) 0.2
Show Answer
Answer: (1)
Solution
$v_d = \frac{I}{neA} = \frac{1.5}{9 \times 10^{28} \times 1.6 \times 10^{-19} \times 5 \times 10^{-6}} \approx 0.02$ mm/s.
BETA
