Answer:
The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet very strong. In fact, electromagnets are the strongest magnets made. An electromagnet is stronger if there are more turns in the coil of wire or there is more current flowing through it.
Answer:
Part a)
Mass of m2 is given as

Part b)
Angular acceleration is given as

Part c)
Tension in the rope is given as

Explanation:
Part a)
When m1 and m2 both connected to the cylinder then the system is at rest
so we can use torque balance here




Part b)
When block m_2 is removed then system becomes unstable
so force equation of mass m1

also we have

now we have




so angular acceleration is given as



Part c)
Tension in the rope is given as



Explanation:
For a circular orbit v=
with G = 6.6742 × 
Given m = 6.42 x 10^23 kg and r=9.38 x 10^6 m
=> v = 2137.3 m/s
I hope this is the correct way to solve
Explanation:e=mwS
<em>and also yes it is i think </em>