Suppose a fixed distance separates the centers of two circular loops. What relative orientation of the loops will give the maximum mutual inductance? What orientation will give the minimum mutual inductance?

A generator coil has 25 turns of wire and a cross-sectional area of 36 $\mathrm{c m}^{2}$. The maximum emf developed in the generator is 2.8 V at 60 Hz. What is the strength of the magnetic field in which the coil rotates?

A loop with 37 turns and an area of 0.33 m2 is rotating at 281 rad/s. The loop's axis of rotation is perpendicular to a uniform magnetic field with a strength of 0.035 T. What is the maximum emf induced? (Hint: Use the expression maximum $\mathrm{emf}=N A B \omega$.)

A. Computers store memory by spinning a stack of magnetic coated plates beneath an electromagnetic head. Suppose a head consists of a 148-turn coil wrapped around an iron ring with an area of $1.25 \times 10^{-8} \mathrm{m}^{2}$. The head is parallel to a magnetic field that changes by $5.2 \times 10^{-4} \mathrm{T} \text { in } 8.5 \times 10^{-9} \mathrm{s}$. What is the induced emf in the coil?

A 256-turn coil with a cross-sectional area of 0.0025 $\mathrm{m}^{2}$ is placed in a uniform external magnetic field of strength 0.25 T so that the plane of the coil is perpendicular to the field. The coil is pulled steadily out of the field in 0.75 s. Find the average induced emf during this interval.

(a) What parameters affect the inductance of a coil? (b) Does the inductance of a coil depend on the current in the coil?

In an RLC series circuit that includes a source of alternating current operating at fixed frequency and voltage, the resistance R is equal to the inductive reactance. If the plate separation of the parallel-plate capacitor is reduced to one-half its original value, the current in the circuit doubles. Find the initial capacitive reactance in terms of R.

A 256-turn coil with a cross-sectional area of $0.0025 \mathrm{m}^{2}$ is placed in a uniform external magnetic field of strength 0.25 Tso that the plane of the coil is perpendicular to the field. The coil is-pulled steadily out of the field in 0.75 s. Find the average induced emf during this interval.

A square, single-turn coil $0.20 \mathrm{~m}$ on a side is placed with its plane perpendicular to a constant magnetic field. An emf of $18 \mathrm{mV}$ is induced in the coil winding when the area of the coil decreases at the rate of $0.10 \mathrm{~m}^2 / \mathrm{s}$. What is the magnitude of the magnetic field?

A proton travels with a velocity of $1.00 \times 10^5 \mathrm{~m} / \mathrm{s}[\mathrm{E}]$. The proton enters a research building that is using a strong magnetic field of $55.0 \mathrm{~T}$. When the proton moves eastward, the magnetic force acting on it is directed straight upward, and when it moves northward, no magnetic force acts on it. (a) Determine the direction of the magnetic field. (b) What is the magnitude of the magnetic force when the proton moves eastward?

Where is the energy of an electromagnetic wave stored? Describe how this energy can be used.

A proton moving perpendicular to a magnetic field of strength 3.5 mT experiences a force due to the field of $4.5 \times 10^{−21}$ N. Calculate the following: the kinetic energy of the proton. Recall that a proton has a charge of $1.60 \times 10^{−19}$ C and a mass of $1.67 \times 10^{−27}$ kg.

A proton moving perpendicular to a magnetic field of strength 3.5 mT experiences a force due to the field of $4.5 \times 10^{−21}$ N. Calculate the following: the speed of the proton. Recall that a proton has a charge of $1.60 \times 10^{−19}$ C and a mass of $1.67 \times 10^{−27}$ kg.

A. A proton moves perpendicularly to a magnetic field that has a magnitude of $4.20 \times 10^{-2} \mathrm{T}$. What is the speed of the particle if the magnitude of the magnetic force on it is $2.40 \times 10^{-14} \mathrm{N}$? Given: Unknown: $B=\frac{F_{\text {magnetic}}}{q v}$