chapter 7 quiz
What is the current in the light?
1.5 A
A transformer with 20 turns is plugged into an electric outlet at 120 V and a light at 8 ohms is plugged into the transformer with two additional turns. What is the voltage at the output coil?
12 V
A transformer has 1,000 turns of wire in the primary coil and 50 turns in the secondary coil. If the input voltage is 2400 volts, what is the output voltage?
120 volts
A transformer increases the input voltage from 12 V to 12,000 V. What is the ratio of the number of wire turns on the primary coil to the number of turns on the secondary coil?
1:1,000
Magnetic domains have an average volume of 0.0001 mm3. If a magnet had dimensions for 50 mm by 10 mm by 4 mm, how many domains does the magnet contain?
2*10(7) or 20,000,000 domains
High-voltage power lines transmit electrical energy at 240,000 V. Before the current reaches your home, the voltage is decreased to the standard voltage for a wall socket. If a single step down transformer is used, what is the ratio of turns in the primary coil two turns in the secondary coil?
2,000 turns
A step down transformer reduces a 2400 V current to 120 V. If the primary coil has 500 turns of wire, how many turns of wire are there on the second coil?
25 turns
A transformer has 90 turns in the primary coil and 9 turns in the secondary coil. If the output voltage is 6 V, what is the input voltage?
60 V
You have a transformer with 50 turns in the primary coil. If you want to increase the voltage from 5 V to 6 V, how many turns should be in the secondary coil?
60 turns
Which change occurs in an electric motor?
Electrical energy into mechanical energy
Atoms at the north pole of a magnet have ...
North and South magnetic poles
Is the transformer a step up transformer or a step down transformer?
Step down transformer
Which is not part of a generator?
battery
What happens to the magnetic force and the distance between two magnetic poles decreases?
increases
Which describes the direction of the electric current in AC?
it varies regularly