# A solenoid of a radius R wound with n turns per unit lengthcarries a current given by I = I0e −βt, where t is the time and β > 0.What are the magnitude and direction of the induced electric field justoutside the solenoid?

Question

A solenoid of a radius R wound with n turns per unit length
carries a current given by I = I0e −βt, where t is the time and β > 0.
What are the magnitude and direction of the induced electric field just
outside the solenoid?