To solve this problem it is necessary to apply the definition given in Faraday's law in a solenoid for which it is noted that
[tex]\epsilon = - d\frac{\phi_B}{dt}[/tex]
[tex]\epsilon = -NA\frac{dB}{dt}[/tex]
Where,
N = Number of loops
A = Cross sectional Area
B = Magnetic Field
[tex]\epsilon = (15)(\pi(0.03)^2)\frac{0-0.5}{0.1}[/tex]
[tex]\epsilon = 0.212V[/tex]
[tex]\epsilon = 0.21V[/tex]
Therefore the correct answer is A.
