Solution:
A temporary strong magnet is created by running current via a coil coiled around a piece of soft iron. It’s a man-made magnet.
The strength of an electromagnet’s magnetic field is determined by:
(i) Number of turns:
As the number of turns of the solenoid’s winding rises, the magnetic strength increases.
(ii) Current:
As the current through the solenoid increases, the magnetic field strength increases.
and 
, internal resistance 
and 
, connected in parallel. The equivalent emf of the combination is- (A) 
(B) 
(C) 
(D) 
and 
are collinear, prove that 
and 
be three points such that area of a 
is 4 sq units, find the value of 
. for which the area of a ABC having vertices 
and 
is 35 sq units. for which the points 
and 
are collinear. for which the points 
and 
are collinear. for which the points 
and 
are collinear.
and 