YASH CLASSES
4 MAGNETIC EFFECTS OF ELECTRIC CURRENT [ X ]
24. A coil of insulated copper wire is connected
to
a galvanometer . what happen
if bar
magnet
is (a) pushed
into the coil ,
(b)
withdrawn from inside coil
(c)
held stationary inside the coil ?
25. The direction
of induce current
in a
circuit
is given by
(a)Fleming’s left hand rule
(b) right hand grip
rule
(c) Fleming’s left
hand rule
(d) Ampere’s swimming
rule
26. If
A.C. frequency of 50Hz
then the
direction change
in one second is
(a)
50 (b)
100 (c) 25
(d) 200
27. A
charged object at
rest produces
(a)
electric field (b) magnetic field
(c)
both (d) none
of these
28. The magnetic field inside the long straight
carrying
current
(a) zero (b)
decrease as we move its end
(c) increase as we move its end
(d) is the same
at all
point
29. Fuse
wire is made
by
(a)
iron (b) cobalt
(c) nickel (d) tin
30. Why
does a compass
needle get
deflected when
brought near a bar
magnet
?