A circular wire loop of radius a and resistance Ris pulled with constant speed v into a uniform magnetic field B. The loop is perpendicular to the field, and it begins entering the field at time t = 0. Part A Find an expression for the current in the loop from t = 0 until the loop is fully immersed in the field. Express your answer in terms of the variables B, v, R, t, and a.

A circular wire loop of radius a and resistance Ris pulled with constant speed v into a uniform magnetic field B. The loop is perpendicular to the field, and it begins entering the field at time t = 0. Part A Find an expression for the current in the loop from t = 0 until the loop is fully immersed in the field. Express your answer in terms of the variables B, v, R, t, and a.