A coil of 325 turns and an area of $19.5 \times 10^{−4} \mathrm{m}^{2}$ is removed from a uniform magnetic field at an angle of $45^{\circ}$ in 1.25 s. If the induced emf is 15 mV, what is the magnetic field’s strength?

A certain lightbulb is rated at 60.0 W when operating at an rms voltage of 120 V. What is the peak voltage applied across the bulb?

A rectangular coil 0.055 m by 0.085 m is positioned so that its cross-sectional area is perpendicular to the direction of a magnetic field, B. If the coil has 75 turns and a total resistance of $8.7 \Omega$ and the field decreases at a rate of 3.0 T/s, what is the magnitude of the induced current in the coil?

Given a conducting loop and current carrying wire, prove that. where the conducting loop has a square shape of side $L$, the wire is long, perpendicular to the plane in which the square loop is contained, and it passes through the center of the latter. Prove that the magnetic flux through the square loop due to the wire is zero.

Electric guitar strings are made of ferromagnetic materials that can be magnetized. The strings lie closely over and perpendicular to a coil of wire. Inside the coil are permanent magnets that magnetize the segments of the strings overhead. Using this arrangement, explain how the vibrations of a plucked string produce an electrical signal at the same frequency as the vibration of the string.

A student attempts to make a simple generator by passing a single loop of wire between the poles of a horseshoe magnet with a $2.5 \times 10^{−2}$ T field. The area of the loop is $7.54 \times 10^{−3} \mathrm{m}^{2}$ and is moved perpendicular to the magnetic field lines. In what time interval will the student have to move the loop out of the magnetic field in order to induce an emf of 1.5 V? Is this a practical generator?

Why is a longer antenna needed to produce a low-frequency radio wave than to produce a high-frequency radio wave?

The time $t$ required to empty a tank varies inversely as the rate $r$ of pumping. If a pump can empty a tank in $45 \text{~min}$ at the rate of $600 \text{~kL/min}$, how long will it take the pump to empty the same tank at the rate of $1000 \text{~kL/min}$?

Why does electromagnetic radiation obey the inverse-square law?

If you have a fixed magnetic field and a length of wire, how can you increase the induced emf across the ends of the wire?

The lid of a pressure cooker forms a nearly airtight seal. Steam builds up pressure and increases temperature within the pressure cooker so that food cooks faster than it does in an ordinary pot. The system is defined as the pressure cooker and the water and steam within it. Suppose that 2.0 g of water is sealed in a pressure cooker and then vaporized by heating. If 5175 J must be added as heat to completely vaporize the water, what is the change in the water’s internal energy?

The lid of a pressure cooker forms a nearly airtight seal. Steam builds up pressure and increases temperature within the pressure cooker so that food cooks faster than it does in an ordinary pot. The system is defined as the pressure cooker and the water and steam within it. Suppose that 2.0 g of water is sealed in a pressure cooker and then vaporized by heating. Is energy transferred as work to or from the system?

The lid of a pressure cooker forms a nearly airtight seal. Steam builds up pressure and increases temperature within the pressure cooker so that food cooks faster than it does in an ordinary pot. The system is defined as the pressure cooker and the water and steam within it. Suppose that 2.0 g of water is sealed in a pressure cooker and then vaporized by heating. Is energy transferred as heat to or from the system?

How much work is done when a tire's volume increases from $35.25 \times 10^{-3} \mathrm{m}^{3} \text { to } 39.47 \times 10^{-3} \mathrm{m}^{3}$ at a pressure of $2.55 \times 10^{5} \mathrm{Pa}$ in excess of atmospheric pressure? Is work done on or by the gas?