Answer:
Radius, r = 0.00523 meters
Explanation:
It is given that,
Magnetic field, 
Current in the toroid, I = 9.6 A
Number of turns, N = 6
We need to find the radius of the toroid. The magnetic field at the center of the toroid is given by :

r = 0.00523 m
or

So, the radius of the toroid is 0.00523 meters. Hence, this is the required solution.
Answer:
M.A = load/ effort
1200N/400N
= 3
velocity ratio= radius of wheel/radius of Axle
40cm/10cm
=4
efficiency= 3/4*100
75%
In both magnitude and direction since acceleration is a vector quantity
Answer:
mass goes down volume remains the same