A generator connected to the wheel or hub of a bicycle can be used to power lights or small electronic devices. A typical bicycle generator supplies 6.00 V when the wheels rotate at $\omega=20.0$ rad/s. Find the time interval between the maximum emf of +6.00 V and the minimum emf of -6.00 V.

In one of NASA's space tether experiments, a 20.0-km long conducting wire was deployed by the space shuttle as it orbited at 7860 m/s around earth and across earth's magnetic field lines. The resulting motional emf was used as a power source. If the component of earth's magnetic field perpendicular to the tether was $1.50 \times 10^{-5} \mathrm{~T}$, determine the maximum possible potential difference between the two ends of the tether.

Inductive charging is used to wirelessly charge electronic devices ranging from toothbrushes to cell phones. Suppose the base unit of an inductive charger produces a $1.00 \times 10^{- 3}$-T magnetic field. Varying this magnetic field magnitude changes the flux through a 15.0-turn circular loop in the device, creating an emf that charges its batter y. Suppose the loop area is $3.00 \times 10^{-4} \mathrm{m}^{2}$ and the induced emf has an average magnitude of 5.00 V. Calculate the time required for the magnetic field to decrease to zero from its maximum value.

A technician wearing a circular metal band on his wrist moves his hand into a uniform magnetic field of magnitude 2.5 T in a time of 0.18 s. If the diameter of the band is 6.5 cm and the field is at an angle of $45 ^ { \circ }$ with the plane of the metal band while the hand is in the field, find the magnitude of the average emf induced in the band.

A magnetic field of magnitude 0.300 T is oriented perpendicular to the plane of a circular loop. Calculate the new magnetic flux if the loop radius is doubled.

(a) A bicycle generator rotates at 1875 rad/s, producing an 18.0 V peak emf. It has a 1.00 by 3.00 cm rectangular coil in a 0.640 T field. How many turns are in the coil? (b) Is this number of turns of wire practical for a 1.00 by 3.00 cm coil?

A magnetic field of magnitude 0.300 T is oriented perpendicular to the plane of a circular loop. Calculate the loop radius if the magnetic flux through the loop is 2.70 Wb.

A 100-turn square coil of side 20.0 cm rotates about a vertical axis at $1.50 \times 10^{3}$ rev/min. The horizontal component of the Earth’s magnetic field at the coil’s location is equal to $2.00 \times 10^{-5} \mathrm{T}.$ (a) Calculate the maximum emf induced in the coil by this field. (b) What is the orientation of the coil with respect to the magnetic field when the maximum emf occurs?

A long, straight wire carrying a current of 2.00 A is placed along the axis of a cylinder of radius 0.500 m and a length of 3.00 m. Determine the total magnetic flux through the cylinder.

A uniform magnetic field of magnitude 0.50 T is directed perpendicular to the plane of a rectangular loop having dimensions 8.0 cm by 12 cm. Find the magnetic flux through the loop.

What is the magnetic field strength at the center of the semicircle.

A circular coil enclosing an area of 100 cm$^2$ is made of 200 turns of copper wire. The wire making up the coil has resistance of $5.0 \Omega$, and the ends of the wire are connected to form a closed circuit. Initially, a 1.1-T uniform magnetic field points perpendicularly upward through the plane of the coil. The direction of the field then reverses so that the final magnetic field has a magnitude of 1.1 T and points downward through the coil. If the time required for the field to reverse directions is 0.10 s, what is the average current in the coil during that time?

In the mentioned Figure, a rectangular loop carrying current lies in the plane of a uniform magnetic field of magnitude $25 \mathrm{~mT}$. The loop consists of a single turn of flexible conducting wire that is wrapped around a flexible mount such that the dimensions of the rectangle can be changed. As edge length $x$ is varied from approximately zero to its maximum value of approximately $4.0 \mathrm{~cm}$, the magnitude $\tau$ of the torque on the loop changes. The maximum value of $\tau$ is $6.2 \times 10^{-8} \mathrm{~N} \cdot \mathrm{m}$. What is the current in the loop?

What current is required in the windings of a long solenoid that has 1000 turns uniformly distributed over a length of $0.400 \mathrm{~m}$, to produce at the center of the solenoid a magnetic field of magnitude $1.00 \times 10^{-4} \mathrm{~T}$ ?