If the current in the solenoid is ramped at a constant rate from zero to I s = 2

Question

If the current in the solenoid is ramped at a constant rate from zero to Is= 2.80 A over a time interval of 85.0 ms, what is the magnitude of the emf in the outer coil while the current in the solenoid is changing?

What is the mutual inductance between the solenoid and the short coil?

Now reverse the situation. If the current in the short coil is ramped up steadily from zero to Ic= 3.60 A over a time interval of 22.0 ms, what is the magnitude of the emf in the solenoid while the current in the coil is changing?

A very long solenoid with a circular cross section and radius r1= 1.60 cm with ns= 180 turns/cm lies inside a short coil of radius r2= 3.90 cm and Nc= 31 turns.

Explanation / Answer

Cant see the image

180 turns/cm = 18000 turns/metre

The field from the solenoid is B = 0.n.I
So the rate of change of this field. dB/dt = 0.n.dI/dt
= 4x10^-7 x 18000 x 2.80/(85.0x10^-3) = 0.745112

The area of the outer coil = x 0.0390^2 = 0.00477836 = 4.78*10^-3

Induced emf = rate of change of flux linkage = NA(dB/dt) = 31 x 4.78*10^-3 * 0.745112
= 0.1104 V

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.