1.
What would you use to measure the mass difference between two like objects?
Correct Answer
D. Density
Explanation
Density is the correct answer because it is a measure of mass per unit volume. By comparing the densities of two like objects, we can determine the difference in their masses. Length, temperature, and speed do not provide information about mass, making them incorrect choices for measuring the mass difference between two objects.
2.
What kind of power do sailboats use?
Correct Answer
C. Wind
Explanation
Sailboats use wind power to propel themselves. The sails on a sailboat are designed to catch the wind, which then pushes the boat forward. By adjusting the angle of the sails and the direction of the boat, sailors can harness the power of the wind to navigate in different directions. This makes wind the primary source of power for sailboats, allowing them to move without the need for fuel or electricity.
3.
What is the smallest possible electricity within an atom called?
Correct Answer
D. Charge
Explanation
The smallest possible electricity within an atom is called charge. Charge refers to the fundamental property of matter that gives rise to electrical interactions. It can be positive or negative, and particles with the same charge repel each other, while particles with opposite charges attract each other. In an atom, the charge is carried by subatomic particles called protons, which have a positive charge, and electrons, which have a negative charge. The balance between the positive charge of protons and the negative charge of electrons determines the overall charge of an atom.
4.
What is moving electricity called?
Correct Answer
A. Current
Explanation
Current is the correct answer because it refers to the movement of electric charge in a conductor. It is the flow of electrons or charged particles through a circuit or medium. Current is measured in Amperes (A) and is essential for the functioning of electrical devices and systems.
5.
What kind of circuit has no breaks in it?
Correct Answer
C. Closed
Explanation
A closed circuit is a type of circuit that has no breaks in it. In a closed circuit, the current can flow continuously from the power source through the various components and back to the source. This allows the circuit to function properly and for electricity to be utilized. In contrast, an open circuit has a break in it, which prevents the flow of current and causes the circuit to be incomplete. Therefore, a closed circuit is the correct answer as it accurately describes a circuit with no breaks.
6.
What happens is a circuit is opened?
Correct Answer
C. The Electric Flow Stops
Explanation
When a circuit is opened, it means that the circuit is broken or disconnected at some point, interrupting the flow of electric current. As a result, the electric flow stops because there is no longer a complete path for the current to travel through. This can be compared to turning off a switch or unplugging a device, where the circuit is opened and the flow of electricity is halted.
7.
What device would you use to open and close a circuit?
Correct Answer
C. Switch
Explanation
A switch is a device that can be used to open and close an electrical circuit. It acts as a bridge between two points in a circuit, allowing or interrupting the flow of electricity. By flipping the switch, the circuit can be either completed or broken, controlling the flow of current. Unlike a paddle or a press, which are not typically used for this purpose, a switch is specifically designed for the task of opening and closing circuits. A nail, on the other hand, is not suitable for this function as it lacks the necessary mechanism to control the circuit.
8.
What is the wire that gives off light in a light bulb?
Correct Answer
C. Filament
Explanation
The filament is the correct answer because it is the part of a light bulb that gives off light. When an electric current passes through the filament, it heats up and emits light. This is known as incandescence and is the principle behind how traditional incandescent light bulbs work. The filament is typically made of tungsten, which has a high melting point and can withstand the heat generated.
9.
What type of electric cells can be charged up again and again?
Correct Answer
C. Rechargeable
Explanation
Rechargeable electric cells can be charged up again and again. These cells are designed to be reusable, allowing them to be recharged and used multiple times before needing to be replaced. This makes them a more cost-effective and environmentally friendly option compared to non-rechargeable cells, which can only be used once and then discarded. Rechargeable cells are commonly used in a variety of electronic devices such as smartphones, laptops, and electric vehicles.
10.
What is it called when a current skips part of the circuit?
Correct Answer
A. Short Circuit
Explanation
A short circuit occurs when a current takes a different path in a circuit, bypassing part of it. This can happen when there is a low resistance connection between two points in the circuit, causing a large amount of current to flow through this unintended path. This can be dangerous as it can cause overheating, damage to the circuit, and even electrical fires.
11.
What places on a magnet have the strongest attraction?
Correct Answer
D. Poles
Explanation
The poles of a magnet have the strongest attraction because they are the ends where the magnetic field lines converge or diverge. These regions have a concentrated magnetic force, which allows magnets to attract or repel each other. The left side, middle, and right side of a magnet do not have the same level of magnetic strength as the poles.
12.
What was magnetite called by the early Europeans?
Correct Answer
D. Lodestone
Explanation
Magnetite was called "Lodestone" by the early Europeans. Lodestone is a naturally occurring magnetic mineral that has the ability to attract iron. The name "Lodestone" comes from the Middle English word "lode" which means "way" or "course," and "stone" referring to the mineral itself. The early Europeans recognized the unique properties of magnetite and its ability to point towards the Earth's magnetic poles, making it a valuable navigational tool.
13.
What force is used to make maglev trains run along their tracks?
Correct Answer
A. Magnetism
Explanation
Maglev trains use magnetism to run along their tracks. The trains are equipped with powerful magnets that create a magnetic field. This magnetic field interacts with the magnets on the tracks, causing a repulsive force that lifts the train slightly above the tracks. As the train moves forward, the magnetic field continuously adjusts to keep the train levitated and stable. This eliminates the need for wheels or any contact with the track, allowing the train to achieve high speeds and a smooth ride.
14.
What electrical term is AC an abbreviation for?
Correct Answer
A. Alternating Current
Explanation
AC is an abbreviation for Alternating Current. Alternating Current refers to the flow of electric charge that periodically reverses direction. Unlike Direct Current (DC), which flows in only one direction, AC changes direction at regular intervals. This type of current is commonly used in electrical power systems, allowing for the efficient transmission of electricity over long distances.
15.
What are the component parts of a battery called?
Correct Answer
D. Electric Cells
Explanation
The component parts of a battery are called electric cells. Electric cells are the individual units within a battery that convert chemical energy into electrical energy. These cells contain electrodes, electrolytes, and a separator, which work together to generate and store electrical energy.