1.
1.
A chair is
dragged across four surfaces – lino, carpet, concrete and ice. Over which
surface would the chair experience the LEAST
friction?
Correct Answer
D. (d) the ice
Explanation
The chair would experience the least friction on the ice surface because ice has a very low coefficient of friction. The smoothness and slipperiness of the ice surface reduces the resistance between the chair and the ice, resulting in less friction compared to the other surfaces.
2.
11.
If a force
can act upon an object without touching it, what do we classify the force as?
Correct Answer
C. The force is a non-contact force
Explanation
A non-contact force is a force that can act upon an object without physical contact. This means that the force can exert an influence on an object from a distance without any direct interaction. Examples of non-contact forces include gravitational force, magnetic force, and electrostatic force. These forces can affect objects without the need for physical contact, making them non-contact forces.
3.
1.
Gravity can best be described as …
Correct Answer
A. A force that pulls you towards the centre of the Earth
Explanation
Gravity is a force that pulls objects towards the center of the Earth. This force is responsible for keeping objects on the ground and causing objects to fall when dropped. It is an attractive force that acts between any two objects with mass.
4.
1.
What is a
force?
Correct Answer
B. A push or a pull
Explanation
A force is defined as a push or a pull. It is a physical interaction between two objects that causes a change in their motion or shape. Forces can be exerted through direct contact or at a distance, such as gravity pulling objects towards the Earth. This definition encompasses the basic concept of force and its fundamental role in the study of physics.
5.
1.
What
happens when you put two magnets together end to end?
Correct Answer
B. North and North push each other away
Explanation
When two magnets with the same polarity (in this case, both magnets have their north poles facing each other) are put together end to end, they will push each other away. This is because like poles repel each other due to the magnetic force between them.
6.
1.
If a paper
clip and a piece of wood entered a magnetic field, what would happen?
Correct Answer
D. The paper clip would be attracted to the magnet, but the wood would not
Explanation
The paper clip would be attracted to the magnet because it is made of a material, such as iron, that is magnetic and can be magnetized. On the other hand, wood is not magnetic and does not contain any magnetic properties, so it would not be affected by the magnetic field and would not be attracted to the magnet.
7.
1.
Which of
the following is an example of Electrostatic
Force?
Correct Answer
A. Holding a charged balloon above your hair, so your hair rises and sticks to the balloon
Explanation
When a charged balloon is held above the hair, the balloon becomes charged with static electricity. The positively charged hair is attracted to the negatively charged balloon due to electrostatic force, causing the hair to rise and stick to the balloon. This phenomenon demonstrates the interaction between charged objects and the force of attraction or repulsion between them, which is the basis of electrostatic force.
8.
1.
Which of
the following is INCORRECT?
Correct Answer
D. Forces cannot bend or twist things
Explanation
Forces can bend or twist things. Forces can cause objects to change their shape or deform them.
9.
1.
Which of
the following is INCORRECT?
Correct Answer
D. When you jump off the ground, the forces acting on you are balanced
10.
1.
Forces are
measured in Newtons. How many Newtons are required to move a 1 kg bag of sugar?
Correct Answer
B. 10 N
Explanation
To move a 1 kg bag of sugar, a force of 10 N is required. This is because the weight of an object can be calculated by multiplying its mass (1 kg) by the acceleration due to gravity (10 m/s^2). Therefore, the force required to overcome the weight of the bag of sugar is 10 N.
11.
1.
What are
the names of the instruments we use to measure forces?
Correct Answer
A. Spring balances, Newtonmeters and scales
Explanation
Spring balances, Newtonmeters, and scales are the instruments used to measure forces. Spring balances are devices that use the principle of Hooke's law to measure the force exerted on them. Newtonmeters, also known as force meters or force gauges, are specifically designed to measure forces in newtons. Scales are used to measure the weight of an object, which is a force due to gravity. Together, these instruments provide various options for measuring different types and magnitudes of forces.
12.
1.
Which of
the following is INCORRECT, in terms
of friction?
Correct Answer
B. Friction does not oppose motion or movement
Explanation
Friction is a force that occurs when two surfaces move past each other. It opposes motion or movement, which means it acts in the opposite direction to the applied force. This is why it is incorrect to say that friction does not oppose motion or movement.
13.
1.
Which of
the following is NOT a method of reducing
friction?
Correct Answer
D. Covering the surfaces in wax
Explanation
Covering the surfaces in wax is not a method of reducing friction because wax can actually increase friction between surfaces. Wax is a sticky substance that can create more resistance between two surfaces, making it harder for them to slide or move smoothly. Therefore, using wax to cover surfaces would not help in reducing friction.
14.
1.
Which of
the following experiences the strongest Gravitational
(Attractive) Force?
Correct Answer
A. You and the Earth
Explanation
The correct answer is "You and the Earth." The gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Since the mass of the Earth is much larger than the mass of an individual, the gravitational force between you and the Earth is stronger than any other pair of objects listed.
15.
1.
Which of
the following is TRUE?
Correct Answer
D. Only your weight changes when you go to the Moon. Your mass stays the same.
Explanation
Weight is a measure of the force of gravity acting on an object, while mass is a measure of the amount of matter in an object. On the Moon, the force of gravity is about 1/6th of that on Earth, so a person would weigh less on the Moon than they would on Earth. However, their mass would remain the same because mass is an intrinsic property of an object and does not change with location.
16.
1.
Which of
the following is INCORRECT?
Correct Answer
D. All materials can be turned into magnets
Explanation
The statement "All materials can be turned into magnets" is incorrect. Not all materials can be turned into magnets. Only certain materials, such as iron, nickel, and cobalt, have magnetic properties and can be attracted to magnets.
17.
1.
Which of
the following is TRUE?
Correct Answer
C. Compasses rely on the Earth’s magnetic field to work
Explanation
Compasses rely on the Earth's magnetic field to work because they are designed to align with the Earth's magnetic field. The Earth acts as a giant magnet with its magnetic field lines running from the geographic North Pole to the geographic South Pole. The compass needle, which is a small magnet, aligns itself with the Earth's magnetic field, allowing us to determine the direction of North and South.
18.
1.
Aurora
Australis (The Southern Lights) are caused by:
Correct Answer
B. Charged particles from the Sun, that are attracted to the South Pole
Explanation
Charged particles from the Sun, that are attracted to the South Pole, cause the Aurora Australis (The Southern Lights). These charged particles, also known as solar wind, are made up of electrons and protons that are emitted by the Sun. When these particles reach the Earth's atmosphere, they interact with gases such as oxygen and nitrogen, causing them to emit light. The South Pole is particularly susceptible to these lights because of its magnetic field, which attracts the charged particles. This phenomenon creates the beautiful light display known as the Aurora Australis.
19.
1.
There are
two types of electric charges. They are:
Correct Answer
B. Positive and Negative Charges
Explanation
The correct answer is "Positive and Negative Charges". This is because positive and negative charges are the two fundamental types of electric charges. Positive charges are associated with protons, which have a positive charge, while negative charges are associated with electrons, which have a negative charge. These charges attract each other, creating an electric force.
20.
1.
There are
laws that tell us how Charged particles behave. Which of the following laws is INCORRECT?
Correct Answer
D. Two opposite charges will attract each other
Explanation
This statement is incorrect because two opposite charges will indeed attract each other. The correct statement would be "Two opposite charges will repel each other."
21.
1.
Electric
charges build up on objects due to the friction between them. The build up of
these electric charges is called static electricity. The word “static” means:
Correct Answer
B. Stationary
Explanation
The word "static" means stationary. In the context of static electricity, it refers to the build-up of electric charges on objects that do not move or flow. This build-up occurs due to friction between objects, causing the charges to remain stationary on the surface of the objects.
22.
1.
Electrostatic
force is similar to Magnetic force. Which of the following do they NOT have in common?
Correct Answer
C. Both forces are created by charged particles
Explanation
Both forces have a field – an area in which the force will act on another object. Both forces are non-contact. Both forces can exert a push or a pull.
23.
1.
When
electric current flows through a wire, it produces a magnetic field. What is
this effect called?
Correct Answer
D. Electromagnetism
Explanation
When electric current flows through a wire, it generates a magnetic field. This phenomenon is known as electromagnetism.
24.
1.
The
magnetic field of a wire can be made stronger if the wire is wound in a coil,
and a bar of iron is placed inside the coil. What name do we give this tightly
coiled wire that produces a magnetic field?
Correct Answer
A. Solenoid
Explanation
A solenoid is a tightly coiled wire that produces a magnetic field. When a bar of iron is placed inside the coil, the magnetic field becomes stronger due to the iron's ability to enhance the magnetic field. Solenoids are commonly used in various applications such as electromagnets, transformers, and inductors.
25.
1.
Forces
can:
Correct Answer
D. All of the above
Explanation
Forces are capable of starting and stopping motion, changing the direction of motion, and speeding up or slowing down motion. This is because forces can exert a push or pull on an object, which can cause it to move or change its motion in various ways. Therefore, all of the given options are correct.