Answer:
a) E = 0.0048 Volts
b) dA/dt = - 0.002285 m²/s
Explanation:
Given:
Area, A = 0.020 m²
Rate of change of magnetic field, dB/dt = 0.24 T/s
a) The magnitude of the emf induced (E) is given as:
E= A × (dB/dt)
on substituting the values in the above equation, we get
E = (0.020 m²) × (0.24 T/s)
or
E = 0.0048 Volts
b) Now, The induced emf when both the area and the magnetic field is varying
we have
E = B(dA/dt) + A(dB/dt)
Now, for the given case induced emf is zero i.e E = 0 and magnetic field B = 2.1 T
thus,
0 = (2.1 T)(dA/dt) + (0.020 m2)(0.24 T/s)
dA/dt = - 0.002285 m²/s
Hence, the area should be decreased at the rate of 0.002285 m²/s