Chapter 21, Problem 9

Chapter 21, Problem 9

A x₁ cm × x₂ cm rectangular circuit containing a x₃ Ω resistor is perpendicular to a uniform magnetic field that start out at x₄ T and steadily decreases at x₅ T/s. 

While this field is changing, what does the ammeter read?  (What is electric current in the circuit?)

Electrodynamics → Electromagnetic Induction: Problem 1

A metal disc...

A metal disc of radius R = x₁ cm rotates with a constant angular velocity ω = x₂ rad/s about its axis. Find the potential difference between the centre and the rim of the disc if

(a) the external magnetic field is absent;

(b) the external uniform magnetic field B = x₃ mT is directed perpendicular to the disc.

Solutions: Chapter 21, Problems 4, 7

Chapter 21, Problem 4. A single loop of wire with an area of x₁ m² is in a uniform magnetic field that has an initial value of x₂ T, is perpendicular to the plane of the loop, and is decreased with the constant rate of x₃ T/s.
(a) What emf is induced in this loop?

(b) If the loop has a resistance of x₄ Ω, find the current induced in the loop.

Chapter 21, problem 7. A closely wound rectangular coil of N turns has dimensions of x₁ cm by x₂ cm. The plane of the coil is rotated from a position where it makes an angle of x₃ᵒ with a magnetic field of x₄ T to a position perpendicular to the field. The rotation takes x₅ s.
What is average emf induced on the coil?

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Math Pictures and Formulae