A circular loop in the plane of the paper lies in a 0.65-T uniform magnetic field pointing into the paper. The loop’s diameter changes from 20.0 cm to 8.0 cm in 0.50 s. What is (a) the direction of the induced current, (b) the magnitude of the average induced emf, and (c) the average induced current if the coil resistance is 2.5Ω?

A rocket zooms past the earth at v=2.0×10⁶ m/s. Scientists on the rocket have created the electric and magnetic fields shown in FIGURE EX31.4. What are the fields measured by an earthbound scientist?

The magnetic flux through a coil of wire containing two loops changes at a constant rate from -68 Wb to +48 Wb in 0.42 s. What is the emf induced in the coil?

(II) The area of an elastic circular loop decreases at a constant rate, dA/dt = -3.50 x 10^-2 m²/s. The loop is in a magnetic field B = 0.35 T whose direction is perpendicular to the plane of the loop. At t = 0, the loop has area A = 0.285 m². Determine the induced emf at t = 0, and at t = 2.00 s.

(II) A circular wire loop of radius 𝓇 = 12 cm is in a uniform magnetic field B = 0.400 T with its plane perpendicular to the direction of the field. If the field magnitude begins to decrease at a rate of -0.010 T/s, at what rate should 𝓇 be increasing at this instant so that the induced emf within the loop is zero?

(II) A single circular loop of wire is placed inside a long solenoid with its plane perpendicular to the axis of the solenoid. The area of the loop is A₁ and that of the solenoid, which has n turns per unit length, is A₂. A current I = I₀ cos ωt flows in the solenoid turns. What is the induced emf in the small loop?

(II) The magnetic field perpendicular to a single 13.2-cm-diameter circular loop of copper wire decreases uniformly from 0.760 T to zero. If the wire is 2.25 mm in diameter, how much charge moves past a point in the coil during this operation?

A circular loop of area 12 m² encloses a magnetic field perpendicular to the plane of the loop; its magnitude is B(t) = (8.0 T/s)t. The loop is connected to a 7.5-Ω resistor and a 6.5-pF capacitor in series. When fully charged, how much charge is stored on the capacitor?

What is the energy dissipated as a function of time in a circular loop of 18 turns of wire having a radius of 10.0 cm and a resistance of 2.0 Ω if the plane of the loop is perpendicular to a magnetic field given by B(t) = B₀e⁻ᵗ/ʳ with B₀ = 0.50 T and τ = 0.10 s?