Acircular copper loop is placed perpendicular to a uniform magnetic field of 0.50 t. due to external forces, the area of the loop decreases at a rate of 1.26 x 10^-3 m^2/s. determine the induced emf in the loop.

Explanation:

According to Faraday-Newmann-Lenz, the induced emf in the loop is given by:

(1)

where is the rate of variation of the magnetic flux through the loop.

We know that the magnetic flux through the loop is given by

where B is the magnetic field and A is the area of the loop. Since the magnetic field is constant, we can write the variation of flux as

So eq.(1) becomes

and the problem gives us:

is the magnetic field

is the rate at which the area changes

Substituting into the equation, we find

the answer is neither ball has a charge.

because if they were both positively charged, they will repel each other.

if they were positively and negatively charged, they will seek.

i believe the answer would be:

d. violin, clarinet, french horn, and tuba