Question 3:
A positively-charged particle (alpha-particle) projected towards west is deflected
towards north by a magnetic field. The direction of magnetic field is
(a) towards south (b) towards east
(c) downward (d) upward
Answer:
(d) The direction of the magnetic field can be determined by the Fleming’s left
hand rule. According this rule, if we arrange the thumb, the centre finger, and
the forefinger of the left hand at right angles to each other, then the thumb
points towards the direction of the magnetic force, the centre finger gives the
direction of current, and the forefinger points in the direction of magnetic field.
Since the direction of positively charged alpha particle is towards west, the
direction of current will be the same i.e., towards west. Again, the direction
of magnetic force is towards north. Hence, according to Fleming’s left hand rule,
the direction of magnetic field will be upwards.
Latest Govt Job & Exam Updates: