1.
Physics is defined as:
Correct Answer
B. The study of matter and its motion through space and time.
Explanation
Physics is a natural science that seeks to understand and explain the fundamental principles governing the behavior of matter, energy, space, and time. It involves the study of various phenomena, including motion, forces, energy, heat, light, sound, electricity, magnetism, and the structure of atoms and particles.
2.
What is the flow of electric charges called?
Correct Answer
B. Electric current
Explanation
Electric current is the flow of electric charges in a conductor. It is the movement of electrons or charged particles through a closed circuit. Electric current is measured in amperes (A) and is responsible for the transfer of energy and the functioning of electrical devices. Electric conductance refers to the ability of a material to conduct electric current, while electric potential refers to the electric potential energy per unit charge. Therefore, the correct answer is electric current.
3.
Name 2 famous physicists who contributed to the understanding of electricity.
Correct Answer(s)
C. Michael Faraday
E. James Clerk Maxwell
Explanation
Michael Faraday and James Clerk Maxwell are two famous physicists who made significant contributions to the understanding of electricity. Faraday discovered electromagnetic induction and formulated laws of electrolysis, while Maxwell unified the theories of electricity and magnetism through his equations, predicting the existence of electromagnetic waves.
4.
What is the S.I. unit of electric current?
Correct Answer
C. Ampere
Explanation
The S.I. unit of electric current is Ampere. Ampere is defined as the amount of electric charge passing through a given point in a circuit per unit time. It is named after the French mathematician and physicist André-Marie Ampère, who made significant contributions to the field of electromagnetism. The unit is commonly used to measure the flow of electric current in various electrical devices and systems.
5.
What is the definition of displacement?
Correct Answer
B. A vector that points from an object's initial position to its final position and has a magnitude that equals the shortest distance between two points
Explanation
In the context of physics, displacement is defined as a change in the position of an object. It is a vector quantity, which means it has both magnitude and direction. The magnitude of the displacement vector is the shortest distance between the initial and final positions of the object, and the direction is from the initial position to the final position. Displacement is different from distance traveled, as it only considers the straight line between the starting point and the ending point, not the actual path taken. For example, if you walk in a circle and end up back where you started, your displacement would be zero, even though you traveled a certain distance.
6.
The flow of electric current is opposite to the flow of electrons in a medium
Correct Answer
A. True
Explanation
In a medium, electric current is the flow of charged particles, which are usually electrons. However, the direction of current is defined as the direction in which positive charges would flow. Since electrons have a negative charge, their actual flow is opposite to the direction of current. Therefore, the statement that the flow of electric current is opposite to the flow of electrons in a medium is true.
7.
What is the definition of average velocity?
Correct Answer
A. Average Velocity = displacement/elapsed time.
Explanation
Average velocity is defined as the displacement of an object divided by the elapsed time. Displacement refers to the change in position of an object, while elapsed time is the total time taken for that change to occur. By dividing the displacement by the elapsed time, we can determine the average rate at which an object is changing its position over a given time period. Therefore, the correct answer is "Average Velocity = displacement / elapsed time".
8.
What is the hindrance to the flow of electrical current known as?
Correct Answer
A. Resistance
Explanation
Resistance is the hindrance to the flow of electrical current. It is a property of materials that opposes the flow of electric current through them. When a voltage is applied across a conductor, the resistance causes the flow of current to be reduced. Resistance is measured in ohms and is influenced by factors such as the material's composition, length, cross-sectional area, and temperature.
9.
What is the resistance of a conductor directly proportional to?
Correct Answer
B. Length
Explanation
The resistance of a conductor is directly proportional to its length. This means that as the length of the conductor increases, the resistance also increases. This relationship can be explained by the fact that as the length of the conductor increases, the number of collisions between electrons and atoms within the conductor also increases. These collisions impede the flow of electrons, resulting in a higher resistance. Therefore, the longer the conductor, the higher its resistance will be.
10.
______________ does not reveal about the direction of the motion. To describe how fast an object moves and the direction of its motion, we need the vector concept of _____________.
Correct Answer
A. Speed - Displacement
Explanation
The first blank is filled with "Speed," which is a scalar quantity that measures how fast an object is moving. Speed does not provide information about the direction of motion; it only tells you how fast an object is going.
The second blank is filled with "Displacement," which is a vector quantity. Displacement not only tells you how far an object has moved (distance) but also specifies the direction of its motion. To fully describe an object's motion, both speed and displacement (or velocity) are needed, and displacement or velocity is represented as a vector because it includes both magnitude and direction.