Transformers only work with AC.
If you put DC into a transformer, all that comes out is smoke.
(a)
Answer:
(a) 
(b)
Explanation:
It is given that,
Force acting on the particle, F = 12 N
Displacement of the particle, 
Magnitude of displacement, 
(a) If the change in the kinetic energy of the particle is +30 J. The work done by the particle is given by :

is the angle between force and the displacement
According to work energy theorem, the charge in kinetic energy of the particle is equal to the work done.
So,



(b) If the change in the kinetic energy of the particle is (-30) J. The work done by the particle is given by :


Hence, this is the required solution.
Answer:
a.
, 
Explanation:
From the information given;
Using the work-energy theorem
ΔKE = W = 
K = 
∴

Since
and r_1 = 4, and r_2 = 2 (from the missing diagram which is attached below)
Then;


Answer:
m
Explanation:
At 10am, the minute hand and hour hand are ' 2 hours apart', since the minute hand is at 12pm and hour hand is at 10am.
Angle between the two hands = 2/12 * 360
= 60°
Arc Length = 
= 