Unit 2 Test - Study
A conductor is a material that doesn't allow electrons to flow through it easily.
false
A lightning bolt occurs when billions of protons are transferred at the same time.
false
Argon has no charge because it has the same number of neutrons as it does electrons.
false
Different household appliances use electrical energy at different rates. ____________________
false
The unit of power is the kilowatt-hour.
false
The unit used to measure current is the volt.
false
Voltage difference is measured in amperes.
false
A material through which electrons do NOT easily flow is a(n) ____.
insulator
A/An _____ is a material in which charges will not move easily, whereas a/an _____ is a material that allows charges to move about easily.
insulator, conductor
Electric companies usually sell electrical energy in units of ____.
kilowatt-hours
An area with excess electrons has a net _____ charge; an area with a deficit of electrons has a net _____ charge.
negative, positive
What is the effect on the current in a simple circuit when both the voltage and the resistance are divided by 2?
no change
Resistance is measured in a unit called the ____.
ohm
Two objects will attract one another when they have ____.
opposite charges
A circuit that has two or more branches for electrons to follow is a(n) ____.
parallel circuit
A circuit that has two or more separate paths for electrons to follow is a(n)____.
parallel circuit
_____charges repel, whereas _____ charges attract.
positive, negative
A __________ is described as a device with specific resistance and is used to control current.
resistor
A path that allows only one route for an electric current is called a ____.
series circuit
Electric charge that has accumulated on an object is referred to as ____.
static electricity
Click on all boxes that apply:
the charges are all positive, and C has the highest charge
If two charges are placed near each other, what will happen to the electrostatic force if the distance between them is doubled.
the force would be 1/4 as much.
A fuse is a device used to keep electrical circuits from overheating.
true
The rearrangement of electrons on a neutral object caused by a nearby charged object is called charging by induction.
true
Three rods of different materials P, Q, and R, are charged by various methods. When the rods are brought near each other, the rods P and Q repel each other, while the rods P and R attract each other. Which of the following could be the signs of the charges on the rods?
- - +
A car panel lamp has a resistance of 33 ohms when it is placed across a 12 V battery. What is the current through the circuit?
.36 A
A lamp uses 15 W of power when it is connected across 25 V. What is the current through the lamp?
.60 A
A lightbulb uses 75 W of power when it is connected across a 125 V source. What current does the lamp draw?
.60 A
A motor with an operating resistance of 32 ohms is connected to a voltage source. The current in the circuit is 3.8 A. What is the voltage of the source?
1.2 x 10^2 V
A sensor uses 2.0 10-4 A of current when it is operated by a 3.0 V battery. What is the resistance of the sensor circuit?
1.5 10^4 ohms
A lamp draws a current of 0.50 A when it is connected to a 120 V source? What is the resistance of the lamp?
2.4 x 10^2 ohms
A car battery causes a current of 2.0 A through a lamp and produces 12 V across it. What is the power used by the lamp?
24 W
If Iron has a charge of +2 How many electrons and protons does the atom have.
24 electrons and 26 protons
The current through a lightbulb connected across the terminals of a 125 V outlet is 0.50 A. Assuming 100% efficiency, at what rate does the bulb convert electric energy to light?
63 W
In the circuit shown below, which bulb, when burned out, will cause all other bulbs to stop glowing?
A
Charging by _____ charges a neutral body by touching it with a charged body; whereas charging by _____ charges an object without touching it with a charged body.
B
Looking at the image, which circuit would turn off totally if you unscrewed a light bulb?
Circuit A
Which circuit in this image will be the brightest?
Circuit A
Which of the following is the correct equation to calculate electrical energy?
E = P x T
Which of the following statements is true about electric forces?
Electric forces cause objects to repel or attract each other.
The statement that current is equal to the voltage difference divided by the resistance is known as ____.
Ohm's law
Check all the following that apply to this image.
Option A, D
Which of the following is the correct relationship among power, current, and voltage?
P = I x V
Match the Term with the Correct Definition
atomic number: the number of protons mass number: the number of protons plus electrons charge: the difference between protons and electrons
Electric forces can be either repulsive or attractive, whereas gravitational force is always:
attractive
Electric field lines are directed _____ positive charges and _____ negative charges.
away from, toward
A _____ is described as a device that converts chemical energy to electric energy.
battery
Which of the following is a device designed to open an overloaded circuit and prevent overheating?
circuit breaker
One example of a good conductor is ____.
copper
A/An _____ is described as a closed loop or pathway that allows electric charges to flow.
electric circuit
A/An _____ is described as a flow of charged particles.
electric circuit
