JEE PYQ: Magnetic Effects Of Current Question 31
Question 31 - 2020 (09 Jan 2020 Shift 2)
An electron gun is placed inside a long solenoid of radius $R$ on its axis. The solenoid has $n$ turns/length and carries a current $I$. The electron gun shoots an electron along the radius of the solenoid with speed $v$. If the electron does not hit the surface of the solenoid, maximum possible value of $v$ is:
(1) $\frac{e\mu_0 nIR}{m}$
(2) $\frac{e\mu_0 nIR}{2m}$
(3) $\frac{e\mu_0 nIR}{4m}$
(4) $\frac{2e\mu_0 nIR}{m}$
Show Answer
Answer: (2) $\frac{e\mu_0 nIR}{2m}$
Solution
Max radius $= R/2$. $v_{\max} = \frac{qBR}{2m} = \frac{e\mu_0 nIR}{2m}$.
BETA
