Magnetic Effects Of Current Question 266
Question: An electron is moving with a speed of $ 10^{8},m/\sec $ perpendicular to a uniform magnetic field of intensity B. Suddenly intensity of the magnetic field is reduced to B/2. The radius of the path becomes from the original value of r [MP PET 1993]
Options:
A) No change
B) Reduces to r / 2
C) Increases to 2r
D) Stops moving
Show Answer
Answer:
Correct Answer: C
Solution:
$ r\propto \frac{1}{B} $ i.e. $ \frac{r_{1}}{r_{2}}=\frac{B_{2}}{B_{1}}\Rightarrow r_{2}=\frac{B_{1}}{B_{1}/2}\times r $ = 2r
BETA
