In the above case we can say that power given by external agent to pull the rod must be equal to the power dissipated in the form of heat due to magnetic induction.
Part a)
when we pull the rod with constant speed then power required will be product of force and velocity
here we will have

P = 4 W
v = 4 m/s
now we will have


So external force required will be 1 N
PART B)
now in order to find magnetic field strength we can say

here we know that induced EMF in the wire is E = vBL
so power due to induced magnetic field is given by


by solving above equation we will have

<h2>A is the correct answer!</h2><h3></h3><h3>I'm too lazy to explain :(</h3><h3></h3><h3><em>Please let me know if I am wrong.</em></h3>
The outside magnetic field of a solenoid is similar to that of a bar magnet even though the inside field is strong and uniform.
The source of power in a nuclear power plant is nuclear reactors. These reactors split uranium atoms, releasing energy in the form of heat, in a process called fission. The heat converts water into steam which powers a turbine generator to produce electricity.