Efficiency = (energy that does the job) / (total energy used)
= (45 J) / (120J)
I think you can handle the division.
The distance the spring stretches is the answer.
I hope this helps.
Have a nice day.
Answer:
D) All of these
Explanation:
The magnetic flux through a coil of wire is given by:

where
B is the intensity of the magnetic field
A is the area enclosed by the coil
is the angle between the direction of B and the normal to the area of the coil
Therefore, we see that the magnetic flux depends on all these quantities:
A) the magnetic field
B)the orientation of the field with respect to the region through which it passes
C)the area of a region through which magnetic field passes
So, the correct answer is
D) All of these