Communication Year 9 Science
This test is designed to test all the outcomes for the science topic.
Questions and Answers
- 1.
Name the two types of waves
Explanation
The correct answer is "transverse and longitudinal." This is because there are two main types of waves: transverse waves and longitudinal waves. Transverse waves are characterized by the particles of the medium vibrating perpendicular to the direction of wave propagation, while longitudinal waves have particles that vibrate parallel to the direction of wave propagation. Therefore, the correct answer includes both types of waves.Rate this question:
- 2.
Electromagnetic waves require matter. true or false
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Electromagnetic waves do not require matter to propagate. They can travel through a vacuum, such as in outer space. This is because electromagnetic waves are composed of oscillating electric and magnetic fields, which can travel independently of any material medium. This property allows electromagnetic waves to travel through empty space, making them different from mechanical waves, which require a material medium for propagation.Rate this question:
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- 3.
Longitudinal waves require matter. True or false
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Longitudinal waves are a type of mechanical wave that require a medium (matter) to propagate through. In these waves, the particles of the medium vibrate parallel to the direction of the wave's motion. Examples of longitudinal waves include sound waves and seismic waves. Therefore, it is true that longitudinal waves require matter.Rate this question:
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- 4.
What is Frequency?
- A.
The length of a complete wave
- B.
The number of complete waves / sec
- C.
The speed of the waves
Correct Answer
B. The number of complete waves / secExplanation
Frequency is a measure of how many complete waves occur in a given amount of time. It represents the number of complete cycles or oscillations that a wave completes in one second. Therefore, the correct answer is "the number of complete waves / sec". This answer accurately describes the concept of frequency as it relates to waves.Rate this question:
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- 5.
Complete the velocity formulavelocity=_______ x_________
Correct Answer
frequency wave length
wave length frequencyExplanation
The correct answer is "frequency wave length". This is because velocity is equal to the product of frequency and wavelength. In other words, the speed at which a wave travels is determined by the frequency of the wave (the number of complete cycles per unit of time) and the wavelength (the distance between two corresponding points on the wave).Rate this question:
- 6.
The amplitude of a wave is
- A.
Its length
- B.
Its height
- C.
Its speed
Correct Answer
B. Its heightExplanation
The amplitude of a wave refers to its height. It represents the maximum displacement of a wave from its equilibrium position. In other words, it is the measure of how far the wave deviates from its rest position. The greater the amplitude, the higher the wave will be. Therefore, the correct answer is "its height."Rate this question:
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- 7.
What is frequency of waves measured in?
Correct Answer
hertz
HzExplanation
Frequency of waves is measured in hertz (Hz). Hertz is the unit of measurement for frequency and represents the number of wave cycles that occur in one second. It is commonly used to measure the frequency of various types of waves, such as sound waves, electromagnetic waves, and radio waves.Rate this question:
- 8.
When an AM radio signal is sent a long a carrier wave it creates an a______ m_______ wave
Correct Answer
amplitude modulated
mplitude odulatedExplanation
When an AM radio signal is sent along a carrier wave, it creates an amplitude modulated wave. The term "amplitude modulated" refers to the process of varying the amplitude of the carrier wave in order to encode the audio signal. On the other hand, "mplitude odulated" appears to be a typo or incomplete phrase, as it does not make sense in the context of the question.Rate this question:
- 9.
What sort of waves are radio and tv audio signals sent along?
Correct Answer
carrier waves
carrierExplanation
Radio and TV audio signals are sent along carrier waves. Carrier waves are electromagnetic waves that are modulated with the audio signal to carry the information. The carrier wave acts as a medium to transmit the audio signal over long distances. It allows the signal to be transmitted and received by radios and TVs, which can then decode the signal and reproduce the audio. Without carrier waves, the audio signals would not be able to travel through the air and reach our devices.Rate this question:
- 10.
A digital TV sends its signals in bits. True or False
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
A digital TV does send its signals in bits. In digital communication, information is converted into binary code, which consists of bits (0s and 1s). These bits are then transmitted over the airwaves or through cables to be decoded by the TV receiver. Therefore, it is true that a digital TV sends its signals in bits.Rate this question:
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- 11.
BEcause a digital tv sends its signals in bits the sound and picture are worse quality. True or False
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
False. This statement is not true. The quality of sound and picture in a digital TV is actually better compared to analog TVs. Digital signals are transmitted in bits, which allows for a higher resolution and clearer audio. Digital TV also offers additional features like high-definition (HD) channels and surround sound, further enhancing the viewing experience.Rate this question:
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- 12.
Optic fibers use ________ to carry high frequency light impulses
- A.
Refraction
- B.
Reflection
Correct Answer
B. ReflectionExplanation
Optic fibers use reflection to carry high frequency light impulses. When light enters an optic fiber, it undergoes multiple reflections off the inner walls of the fiber due to total internal reflection. This process allows the light to travel through the fiber without significant loss of intensity or distortion. By reflecting the light, optic fibers ensure that the light pulses can be transmitted over long distances without much degradation, making them ideal for high frequency communication and data transmission.Rate this question:
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- 13.
On a flat reflective surface the angle of incidence does not equal the angle of reflection. True or false
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
False. According to the law of reflection, the angle of incidence is equal to the angle of reflection when light rays hit a flat reflective surface. This means that the direction of the reflected light is symmetric to the direction of the incident light, forming equal angles with the surface normal.Rate this question:
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- 14.
Reflected light rays diverge from a convex mirror. True or False
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
A convex mirror is curved outward, causing light rays to spread out or diverge when they reflect off its surface. This is why objects appear smaller and wider in convex mirrors compared to their actual size. Therefore, the statement "reflected light rays diverge from a convex mirror" is true.Rate this question:
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- 15.
Reflected rays diverge from a concave mirror true or false?
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
False. Reflected rays from a concave mirror converge rather than diverge. This is because a concave mirror is curved inward, causing the rays to meet at a focal point.Rate this question:
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- 16.
What is it called when light bounces off an object?
Correct Answer
reflectionExplanation
When light bounces off an object, it is called reflection. Reflection occurs when light rays strike a surface and bounce back, changing direction. This phenomenon is responsible for allowing us to see objects, as the reflected light enters our eyes. Reflection is a fundamental property of light and is the basis for many optical phenomena, such as mirrors and the reflection of light in water.Rate this question:
- 17.
What is it called when light bends?
Correct Answer
refractionExplanation
Refraction is the phenomenon that occurs when light passes through a medium and changes its direction due to the change in speed. This bending of light is caused by the change in the medium's density or refractive index. When light travels from one medium to another, such as from air to water or from air to glass, it undergoes refraction. This change in direction is what allows us to see objects through lenses, prisms, and other optical devices. Therefore, the term "refraction" accurately describes the bending of light.Rate this question:
- 18.
What is an example of a transverse matter wave?
- A.
Light wave
- B.
Sound wave
- C.
Heat wave
Correct Answer
B. Sound waveExplanation
A transverse matter wave refers to a wave in which the particles of the medium vibrate perpendicular to the direction of wave propagation. Sound waves, on the other hand, are longitudinal waves where particles vibrate parallel to the direction of wave propagation. Therefore, sound waves do not fit the definition of a transverse matter wave.Rate this question:
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- 19.
What is an example of an electromagnetic wave?
- A.
Heat
- B.
Sound
- C.
Water wave
Correct Answer
A. HeatExplanation
An example of an electromagnetic wave is heat. Heat is a form of energy that is transferred through the movement of atoms and molecules. It is a type of electromagnetic radiation that is emitted by objects with a higher temperature and can be detected by our sense of touch or through specialized instruments. Heat waves are a part of the electromagnetic spectrum, which includes other forms of radiation such as visible light, radio waves, microwaves, and X-rays.Rate this question:
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- 20.
What is the speed a wave travels in a straight line is called?
Correct Answer
velocityExplanation
Velocity is the correct answer because it refers to the speed at which a wave travels in a straight line. Velocity is a vector quantity that includes both the magnitude (speed) and direction of motion. In the context of waves, velocity represents how quickly a wave moves from one point to another in a specified direction.Rate this question:
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Mar 17, 2023Quiz Edited by
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Oct 11, 2010Quiz Created by
Laura_rose