Answer:
The value is 
Explanation:
From the question we are told that
The diameter of the ring is 
The length of the solenoid is 
The diameter of the solenoid is 
The number of turns is N = 1500
The change in current in the solenoid is 
The time taken is 
Generally the radius of the ring is

=> 
=> 
Generally the area of the ring is mathematically represented as

=>
=> 
Generally the induced emf is mathematically represented as

Here

Here
is the permeability of free space with value

So

=> 
So

=> 
Answer:
9000 J
Explanation:
Convert minutes to seconds.
2 min = 120 s
Power = energy / time
75 W = E / 120 s
E = 9000 J
Answer:

Explanation:
P = Power = 50 kW
n = Number of photons per second
h = Planck's constant = 
= Frequency = 781 kHz
r = Distance at which the photon intensity is i = 1 photon/m²
Power is given by

Photon intensity is given by

The distance is 
If the wagon travels 18.75 m, then the work done on the wagon is
(18.75 m) x (the steady force applied to the wagon all the way, in Newtons) .
The unit is Joules .
Answer:
i dont understand, can you put it in word form please.
Explanation: