Question

A solenoid with a cross-sectional area of 1.91×10⁻³ m2m2 is 0.680 mm long and has 475 turns per meter.

Find the magnitude of induced emf in this solenoid if the current in it is increased from 0 to 2.40 AA in 50.5 msms .

Answer 1

Given,

​​​​​​

​​​​​​

Turns per unit length (n) = 475​​​​​​ per meter

Now we calculate total number of turns(we give it symbol N)

Induced EMF will be calculated using

Where

Since area and magnetic field are in same direction

Now the Magnetic Field(B)

Where

For current(I_1)

And for current(I_2)

The change in in magnetic flux,

Since,