A simple generator has a square armature $6.0 \mathrm{~cm}$ on a side. The armature has $85$ turns of $0.65 \mathrm{~cm}$ diameter copper wire and rotates in a $0.65 \mathrm{~T}$ magnetic field. The generator is used to power a lightbulb rated at $12.0 \mathrm{~V}$ and $25.0 \mathrm{~W}$. At what rate should the generator rotate to provide $12.0 \mathrm{~V}$ to the bulb? Consider the resistance of the wire on the armature.

Calculate the peak output voltage of a simple generator whose square armature windings are $5.50 \mathrm{~cm}$ on a side; the armature contains $125$ loops and rotates in a field of $0.200 \mathrm{~T}$ at a rate of $120 \mathrm{rev} / \mathrm{s}$.

A generator rotates at $85 \mathrm{~Hz}$ in a magnetic field of $0.030 \mathrm{~T}$. It has $950$ turns and produces an rms voltage of $150 \mathrm{~V}$ and an rms current of $60.0 \mathrm{~A}$. What is the area of each turn of the coil?

A dc motor has coils with a resistance of $16 \Omega$ and is connected to an emf of 120.0 V. When the motor operates at full speed, the back emf is 72 V. (a) What is the current in the motor when it first starts up? (b) What is the current when the motor is at full speed? (c) If the current is 4.0 A with the motor operating at less than full speed, what is the back emf at that time?

A 1500 W heater runs on 120 V rms. What is the peak current through the heater?

A lightbulb is connected to a 120 V (rms), 60 Hz source. How many times per second does the current reverse direction?

A generator rotates at $85 \mathrm{~Hz}$ in a magnetic field of $0.030 \mathrm{~T}$. It has $950$ turns and produces an rms voltage of $150 \mathrm{~V}$ and an rms current of $60.0 \mathrm{~A}$. What is the peak current produced?

A $280$-loop circular armature coil with a diameter of $10.0 \mathrm{~cm}$ rotates at $120 \mathrm{rev} / \mathrm{s}$ in a uniform magnetic field of strength $0.45 \mathrm{~T}$. What would you do to the rotation frequency in order to double the rms voltage output?

A $280$-loop circular armature coil with a diameter of $10.0 \mathrm{~cm}$ rotates at $120 \mathrm{rev} / \mathrm{s}$ in a uniform magnetic field of strength $0.45 \mathrm{~T}$. What is the rms voltage output of the generator?

Two $3.8~\mu \mathrm{F}$ capacitors, two $2.2~\mathrm{k} \Omega$ resistors, and a $16.0 \mathrm{~V}$ source are connected in series. Starting from the uncharged state, how long does it take for the current to drop from its initial value to $1.50 \mathrm{~mA}$ ?

A simple generator has a $440$-loop square coil $22.0 \mathrm{~cm}$ on a side. How fast must it turn in a $0.550\mathrm{~T}$ field to produce a $120~\mathrm{V}$ peak output?

The generator of a car idling at $875 \mathrm{~rpm}$ produces $12.4 \mathrm{~V}$. What will the output be at a rotation speed of $1850 \mathrm{~rpm}$ assuming nothing else changes?

A simple generator is designed to generate a peak output voltage of $24.0 \mathrm{~V}$. The square armature consists of windings that are $5.15 \mathrm{~cm}$ on a side and rotates in a field of $0.380 \mathrm{~T}$ at a rate of $60.0 \mathrm{~rev} / \mathrm{s}$. How many loops of wire should be wound on the square armature?

An electric car has a battery that can hold $16 \mathrm{kWh}$ of energy (approximately $6 \times 10^7 \mathrm{~J}$ ). If the battery is designed to operate at $340 \mathrm{~V}$, how many coulombs of charge would need to leave the battery at $340 \mathrm{~V}$ and return at $0 \mathrm{~V}$ to equal the stored energy of the battery?