Physical Science Ch 8 HW
more than 20 V
A 10 ohm resistor has 5 A current in it. What is the voltage across the resistor?
0.5 A
A 60-W light bulb is connected to a 120-V plug. What is the current in the light bulb?
motor
A device that transforms electrical energy to mechanical energy is a
protons than electrons
A positive ion has more
energy***
A step-up transformer increases
voltage
A transformer actually transforms
current
An ampere is a unit of electrical
increases
As more lamps are put into a parallel circuit, the overall current in the power source
the same
Compared to the amount of electric current that flows in the filament of a lamp, the amount of current that flows in the connecting wire is
less resistance
Compared to the resistance of two resistors connected in series, the same two resistors connected in parallel have
series
In an electric circuit, the safety fuse is connected to the circuit in
attract
Like kinds of magnetic poles repel while unlike kinds of magnetic poles
1:100
Neon signs require about 12,000 V to operate. If the circuit uses a 120-V power source, the ratio of primary to secondary turns on the transformer should be
low so that overheating of the wires is minimized.
Power is transmitted at high voltages because the corresponding current in the wires is
12 A
The current through a 10 ohm resistor connected to a 120-V power supply is
240 W
The electric power of a lamp that carries 2 A at 120 V is
series
The greatest equivalent resistance occurs when the resistors are connected in which type of arrangement?
36 W
The power dissipated in a 4 ohm resistor carrying 3 A is
55 V
The voltage across the input terminals of a transformer is 110 V. The primary has 50 loops and the secondary has 25 loops. The voltage the transformer puts out is
both voltages are the same
Two lamps, one with a thick filament and one with a thin filament, are connected in parallel to a battery. The voltage is greatest across the lamp with the
the same in each lamp
Two lamps, one with a thick filament and one with a thin filament, are connected in series. The current is greater in the lamp with the
ampere
What is the unit of electric current?
amp x volt
What is the unit of electrical power?
ohm
What is the unit of resistance?
volt
What is the unit of voltage?
the magnetic declination
What is the variation in the location of the Earth's magnetic north pole from true north given by?
mechanical energy into electrical energy
What type of energy conversion does a generator perform?
electrical energy into mechanical energy
What type of energy conversion does a motor perform?
5 ohms
When a 10-V battery is connected to a resistor, 2 A of current flow in the resistor. What is the resistor's value?
half as strong as the original magnet.
When a bar magnet is broken in two as shown, each piece is
less than the resistance of either lamp
When two lamps are connected in parallel to a battery, the electrical resistance that the battery senses is
more than the resistance of either lamp
When two lamps are connected in series to a battery, the electrical resistance that the battery senses is
electrical
Which force binds atoms together to form molecules?
none of these****
Which of the following is true of a magnetic field?
it has fewer windings on the primary coil
Which of the following is true of a step-up transformer?
