Determine whether the following statement describes a step-up transformer or a step-down transformer: The primary coil has 7,000 turns, and the secondary coil has 500 turns.

A spacecraft orbiting Earth has a coil of wire in it. An astronaut measures a small current in the coil, although there is no battery connected to it and there are no magnets in the spacecraft. What is causing the current?

A transformer with 1000 turns in its primary coil has to reduce the voltage from 4400 V to 220 V for home use. How many turns must there be on the secondary coil?

Use the terms generator and electromagnetic induction to explain how kinetic energy of falling water is used to generate electrical energy.

A step-up transformer has $30$ turns on the primary coil and $750$ turns on the secondary coil. If this transformer is to produce an output of $4800 \mathrm{~V}$ with a $15-\mathrm{mA}$ current, what input current and voltage are needed?

A can of cola has 41 grams of sugar in each 12-ounce can. If you drink nine cans over the span of a week, how many pounds of sugar have you consumed during that week from the soda?

Explain the difference between a step-up and a step-down transformer.

A transformer used to step up $115 \mathrm{~V}$ to $5000 \mathrm{~V}$ has a primary coil of $100$ turns. What must be the number of turns in the secondary coil?

Determine the direction in which a compass needle will point when held above a wire with positive charges moving west.

Which of the following will not increase the current induced in a wire loop moving through a magnetic field. a. increasing the strength of the magnetic field b. increasing the speed of the wire c. rotating the loop until it is perpendicular to the field

Which of the following would have the strongest magnetic field. Assume the current in each is the same. a. a straight wire b. an electromagnet with 30 coils c. a solenoid with 20 coils d. a solenoid with 30 coils

Explain how galvanometers and electric motors function.

Why is it important that the current in the armature of a motor that uses a permanent magnet periodically change direction?

Predicting Outcomes Predict whether a solenoid suspended by a string could be used as a compass.