E field induced by changing B field

[Zywo]

Homework Statement

The magnetic field inside a 5.0-cm-diameter solenoid is 2.0 T and decreasing at 4.90 T/s
What is the electric field strength inside the solenoid at point on the axis?

Homework Equations

E=(r/2)*(dB/dt)

The Attempt at a Solution

E=(.025/2)*(4.9)= 0.06125 V/m

Not sure what's wrong here...

Thanks,
David

 

[couyang2]

Should be 0 because the distance from the axis is 0.