A long, thin superconducting wire carrying a 17 A current passes through the center of a thin, 3.0-cm-diameter ring. A uniform electric field of increasing strength also passes through the ring, parallel to the wire. The magnetic field through the ring is zero. a. At what rate is the electric field strength increasing?
b. is the electric field in the direction of the current or opposite to the current?

a

b

The  direction of the electric field is opposite that of the current              

Explanation:

From the question we are told that

   The current is  

   The diameter of the ring is  

Generally the  radius is mathematically represented as

The  cross-sectional area is mathematically represented as

=>    

=>    

Generally  according to ampere -Maxwell equation we have that

Now given that it implies that

So

Where   is the permittivity of free space with value

            is the permeability of free space with value  

      is magnetic flux which is mathematically represented as

Where E is the electric field strength

  So  

=>  

=>  

=>  

The  negative  sign shows that the  direction  of  the electric field is opposite that of the current

the answer is ampere

the ampere is used to measure electricity. an ampere is a unit of electric current equal. a unit of measure for the flow of current in a circuit. one ampere is the amount of current flow provided when one volt of electrical pressure is applied against one ohm of resistance.

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.