Acurrent carrying circular loop of wire lies flat on a table top. when viewed from above, the current moves around the loop in a counterclockwise sense. what is the direction of the magnetic field caused by this current, inside the loop? the magnetic field a) circles the loop in a counterclockwise direction. b) points straight up. c) points straight down. d) circles the loop in a clockwise direction. e) points toward the east.

Option (b)

Explanation:

Maxwell right hand thumb rule: if we hold a current carrying conductor in our right hand such taht the thumb indicates the direction of current then the curling of fingers give the direction of magnetic field around the conductor and vice versa.

Here the current is counterclockwise so by use of Maxwell right hand thumb rule the direction of magnetic field is straight up.

For the answer to the question above,
we can get the number of fringes by dividing (delta t) by the period of the light (Which is λ/c). 

fringe = (delta t) / (λ/c) 

We can find (delta t) with the equation: 

delta t = [v^2(L1+L2)]/c^3 

Derivation of this formula can be found in your physics text book. From here we find (delta t): 

600,000^2 x (11+11) / [(3x10^8)^3] = 2.93x10^-13 

2.93x10^-13/ (589x10^-9 / 3x10^8) = 149 fringes 

This answer is correct but may seem large. That is because of your point of reference with the ether which is usually at rest with respect to the sun, making v = 3km/s.