Aptitude Test Problems in Physics Science for Everyone by S Krotov ( PDFDrive.com )

r=--

g qmg)1^2 '

. 1 / 12 (T/27‘)2
(281( T) B1(

280 Aptitude Test Problems in Physics

face area bounded by the loop is zero at any instant
of time. Therefore, the galvanometer will indicate
zero.
3.50. Let us choose the coordinate system sOy
with the origin coinciding with the instantaneous

Fig. 222

position of the ball (Fig. 222). The x-axis is "cen-

tripetal", while the y-axis is vertical just as the

magnetic induction B.

The system of equations describing the motion

of the ball (we assume that the ball moves in a

circle counterclockwise) will be written in the

form

N sin a— gvB —

mv 2

lsina '

N cos a = mg.

Besides,

2nr

= T, r= 1 sin a.

Solving this system of equations, we obtain