Question

Read the passage given below and answer questions 39 and 40 by choosing the correct
alternative
When a charged particle enters a region of uniform magnetic field, it stats experiencing force due to the
magnetic field. The direction of force is given by Fleming's left hand rule and its magnitade is F=qvBsin e.
Where q is the charge on the particle, v is its speed, B is the magnitude of magnetic field and 0 is the angle
between magnetic field and velocity of the particle. Based on this information answer the following
questions (take charge on a proton to be +e).
39. If an a-particle (nucleus of helium) enters in the region of uniform magnetic field such that magnetic
field is directed perpendicular to the velocity of the particle, the work done by magnetic force will be
(B) ev'B
(D) Sev
(A)0
2
40. An clectron beam moving east to west when enters a region of uniform magnetic field directed south will
get deflected
(A) vertically upwards
C) towards north
(B) vertically downwards
(D) towards south
​

Answer 1

Answer:

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