1.
How do like charges act when put near each other?
Correct Answer
B. Repel or pull apart
Explanation
Like charges, such as two positive or two negative charges, repel or push apart from each other. This is due to the electrostatic force, which is the force of attraction or repulsion between electrically charged objects. According to Coulomb's Law, like charges repel each other because they have the same charge, creating a force that pushes them away from each other. Therefore, the correct answer is "repel or pull apart."
2.
In a series circuit, electricity travels on ____________ path(s).
Correct Answer
C. One
Explanation
In a series circuit, electricity travels on one path. This means that the current flows through each component in the circuit one after the other, without any branching or parallel paths. In a series circuit, the total resistance is equal to the sum of the individual resistances, and the current remains the same throughout the circuit. Therefore, the correct answer is one.
3.
Current that flows in one direction is called _________________________.
Correct Answer
B. Direct current
Explanation
Direct current is the flow of electric charge in one direction, usually from a power source such as a battery. It is characterized by a constant and steady flow of electrons in a single path. Unlike alternating current, which periodically changes direction, direct current maintains a consistent polarity. Series current and electric are not accurate terms to describe the flow of current, while alternating current refers to the flow that changes direction periodically.
4.
Most circuits in the school building are _______________ _________________.
Correct Answer
C. Parallel circuit
Explanation
Most circuits in the school building are parallel circuits. In a parallel circuit, the components are connected in such a way that there are multiple paths for the current to flow. This means that if one component fails or is removed, the other components will still receive current and continue to function. In a school building, it is common to have multiple devices connected to the same power source, such as lights, computers, and projectors. Using parallel circuits ensures that each device can operate independently without affecting the others.
5.
In order for current to flow, what do you need to have the following: (Select the correct answers)
Correct Answer(s)
A. Wire
B. Power source
D. Device to use the current ex. light
Explanation
To allow current to flow, three components are necessary: a wire to serve as the conductor, a power source to provide the electrical energy, and a device to utilize the current, such as a light bulb. The wire acts as a pathway for the flow of electrons, the power source supplies the necessary voltage, and the device converts the electrical energy into a desired form, in this case, light. A switch, although commonly used to control the flow of current, is not essential for current to flow.
6.
If you take one light bulb out of a string of bulbs and the rest of them go out, you have what type of circuit.
Correct Answer
D. Series circuit
Explanation
If taking out one light bulb causes the rest of the bulbs to go out, it indicates a series circuit. In a series circuit, the components are connected in a single path, so the current must flow through each component in order for the circuit to function. If one component fails or is removed, it interrupts the flow of current and causes the entire circuit to stop working.
7.
A flashlight is example of what kind of circuit.
Correct Answer
B. Series circuit
Explanation
A flashlight is an example of a series circuit because it has only one path for the current to flow. In a series circuit, the components are connected one after the other, meaning that the current passes through each component in sequence. In the case of a flashlight, the battery is connected to the switch, which is then connected to the bulb. If any component in a series circuit fails or is disconnected, the entire circuit will be interrupted and the flashlight will not work.
8.
What type of natural phenomena is an example of static electricity?
Correct Answer
B. Lightning
Explanation
Lightning is an example of static electricity because it is a sudden discharge of built-up electrical energy in the atmosphere. During a thunderstorm, friction between ice particles and water droplets in the storm clouds creates an imbalance of positive and negative charges. This causes a buildup of static electricity, which is released in the form of a lightning bolt when the electrical potential difference becomes too great.
9.
Current that that flows on more than one path is called_________________.
Correct Answer
D. Parallel circuit
Explanation
A parallel circuit is a type of circuit where the current flows through multiple paths. In this type of circuit, the components are connected in such a way that each component has its own separate path for the current to flow through. This allows the current to divide and flow through different branches simultaneously. Therefore, a parallel circuit is the correct answer for the given question as it describes the situation where current flows on more than one path.
10.
If you have a string of lights and you add another light, all of the lights become dimmer. What type of circuit is this?
Correct Answer
B. Series circuit
Explanation
In a series circuit, the components are connected in a single path, so the current flows through each component one after the other. Adding another light bulb in a series circuit increases the resistance, which decreases the current flowing through the circuit. As a result, all the lights in the circuit become dimmer because they receive less current.
11.
A diagram that uses symbols to show the parts of a circuit.
Correct Answer
C. Schematic
Explanation
A schematic is a diagram that uses symbols to represent the parts of a circuit. It is a simplified and standardized representation that allows for easy understanding and analysis of the circuit. Unlike a conductor, which is a material that allows the flow of electric current, or an insulator, which is a material that prevents the flow of electric current, a schematic is a visual representation of the circuit's components and their connections. Resistance, on the other hand, refers to the opposition to the flow of electric current in a circuit.
12.
A measure of how easily electric current will flow through a material.
Correct Answer
C. Resistance
Explanation
Resistance is a measure of how easily electric current will flow through a material. It is the property of a material to resist the flow of electric charge. Materials with high resistance impede the flow of current, while materials with low resistance allow current to flow more easily. Therefore, resistance is the correct answer in this context.
13.
The type of current in the school building is _________________ current.
Correct Answer
A. Alternating
Explanation
The type of current in the school building is alternating current. Alternating current (AC) is a type of electric current that periodically reverses direction. It is the most common type of current used in homes, buildings, and electrical grids. Unlike direct current (DC), which flows in only one direction, alternating current changes its direction in a cyclic manner. This allows for efficient transmission of electricity over long distances and enables the use of transformers to change voltage levels.
14.
Most circuits in homes or in the school building are ______________.
Correct Answer
B. 120 volts
Explanation
Most circuits in homes or in the school building are typically designed to operate at a voltage of 120 volts. This is the standard voltage used in residential and commercial buildings in many countries, including the United States. It is considered a safe and efficient voltage level for powering household appliances, lighting, and other electrical devices.
15.
Choose the following items that are insulators.
Correct Answer(s)
A. Rubber
C. Plastic
F. Wood
Explanation
Rubber, plastic, and wood are all examples of insulators. Insulators are materials that do not conduct electricity easily. They have high resistance and do not allow the flow of electric current through them. Rubber, plastic, and wood are all commonly used as insulating materials in various applications, such as electrical wiring, to prevent the risk of electric shock or short circuits. Copper, gold, and silver, on the other hand, are all conductors and allow the flow of electric current.
16.
If a hair dryer uses 1.584 kw an hour and you use the hair dryer .5 hours a day, how much energy does the hair dryer use every day?
Correct Answer
B. .792 kwh
Explanation
The hair dryer uses 1.584 kW per hour and is used for 0.5 hours per day. To calculate the energy used every day, we multiply the power (1.584 kW) by the duration (0.5 hours), which gives us 0.792 kWh. Therefore, the hair dryer uses 0.792 kWh of energy every day.
17.
If a halogen lamp uses 12.6 kw of energy in a week, how much does the electricity cost for the lamp if electricity is $.10 an a kWh?
Correct Answer
D. $1.26
Explanation
The cost of electricity for the halogen lamp can be calculated by multiplying the energy usage (12.6 kWh) by the cost per kWh ($0.10). This gives us a total cost of $1.26.
18.
What helps prevent fires when a circuit is overloaded?
Correct Answer
A. Circuit breaker
Explanation
A circuit breaker helps prevent fires when a circuit is overloaded by automatically shutting off the flow of electricity. When a circuit is overloaded, the amount of current passing through the wires exceeds their capacity, causing them to overheat. This overheating can lead to electrical fires. However, a circuit breaker detects this excessive current and trips, breaking the circuit and stopping the flow of electricity. By doing so, it prevents the wires from overheating and reduces the risk of fire.
19.
A field in a region of space around a charge that shows fields of positive or negative charge
Correct Answer
C. Electric field
Explanation
An electric field is a field in a region of space around a charge that shows fields of positive or negative charge. It is the force per unit charge experienced by a charged particle in the presence of other charges. The electric field is created by electric charges and can be either positive or negative depending on the type of charge. It is responsible for the interaction between charged particles and is a fundamental concept in electromagnetism.
20.
Earth is like a giant_______________.
Correct Answer
B. Magnet
Explanation
Earth can be compared to a magnet because it has a magnetic field. This magnetic field is generated by the movement of molten iron in its outer core. Just like a magnet, Earth has a north and south pole, and its magnetic field can attract or repel certain materials. This magnetic field is also responsible for protecting the Earth from harmful solar radiation by deflecting charged particles from the sun.