Asquare wire loop of side l and resistance r is pulled with constant speed v from a region of no magnetic field until it is fully inside a region of constant, uniform magnetic field b⃗ perpendicular to the loop plane. the boundary of the field region is parallel to one side of the loop. find an expression for the total work done by the agent pulling the loop. express your answer in terms of the variables b, l, v and r. w=

where’s the list ? the question is incomplete

because growing process had stoped after 4-5 year

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me