Two electron beams having their velocities in the ratio $$1:2$$ are subjected to identical magnetic fields acting at right angles to the direction of motion of electron beams. The ratio of deflection produced is:
A.
$$2:1$$
B.
$$1:2$$
C.
$$4:1$$
D.
$$1:4$$
Answer :
$$1:2$$
Solution :
Since, magnetic field is acting at right angles to the direction of motion of electron beams, so their paths will be circular.
$$\eqalign{
& r = \frac{{mv}}{{qB}} \cr
& {\text{or}}\,\,r \propto v \cr
& \therefore \frac{{{r_1}}}{{{r_2}}} = \frac{{{v_1}}}{{{v_2}}} = \frac{1}{2} \cr
& {\text{or}}\,\,{r_1}:{r_2} = 1:2 \cr} $$
Releted MCQ Question on Electrostatics and Magnetism >> Magnetic Effect of Current
Releted Question 1
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A.
proportional to $$2\left( {{{180}^ \circ } - \theta } \right)$$
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