Grade 6 Science Unit Evaluation, along with answers, explanations, and the correct answers where relevant.

Here are the questions from the Grade 6 Science Unit Evaluation, along with answers, explanations, and the correct answers where relevant.

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### PART I

1. Underline the most correct answer.

i) Sound is a kind of

- a) Material

- b) Liquid

- c) Energy

Answer: c) Energy

Explanation: Sound is a form of energy that travels through materials (solids, liquids, and gases) as vibrations.

ii) A drum produces sound by vibrating:

- a) An air stem

- b) A wooden stem

- c) A membrane

- d) A string

Answer: c) A membrane

Explanation: The drumhead, or membrane, vibrates when struck, creating sound waves that we hear.

iii) What is the sensory organ for sound energy?

- a) Ear

- b) Eye

- c) Skin

- d) Ear protectors

Answer: a) Ear

Explanation: The ear is the sensory organ responsible for detecting sound energy.

iv) The bicycle bell produces sound by vibrating:

- a) Nail

- b) Metal membrane

- c) String

- d) Air column

Answer: b) Metal membrane

Explanation: The metal membrane or bell's metal surface vibrates, creating sound when struck.

v) Which part of the human body helps to direct sound to the ear?

- a) Ear lobe

- b) Hand

- c) Skin

- d) Ear drum

Answer: a) Ear lobe

Explanation: The outer ear, including the ear lobe, helps direct sound into the ear canal.

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2. Use the given word list to fill in the blanks.

- Word List: responsibility, music, artificial, vibrating, sound sources, unpleasant, loud, ear lobes, nerves, ear

i) It is our responsibility to use sounds without disturbing others.

ii) Sound sung or played rhythmically is known as music.

iii) Some sounds we hear are natural, and some sounds we hear are artificial.

iv) In all instances, sound is made by vibrating.

v) Objects producing sound are called sound sources.

vi) Unrhythmical unpleasant sound is known as a noise.

vii) Loud sound can be harmful to the ear.

viii) Ear lobes help to direct sound into the ear.

ix) Putting external objects to itch the ear can damage the ear, and nerves may be weakened.

x) Ear is the sense organ that helps with hearing.

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### PART II

1. Write 5 natural sources of sound.

Answer:

- Birds chirping

- Wind blowing

- Thunder

- Waterfall

- Animal calls

Explanation: Natural sources of sound come from the environment, not produced by machines or human-made objects.

2. Write 3 instances where we hear noises in our day-to-day life.

Answer:

- Traffic sounds (honking, engines)

- Construction site noise

- Loudspeakers at events

Explanation: Noises in daily life are often caused by human activities and can be disruptive or unpleasant.

3. Write 3 ways of making harm to the ear.

Answer:

- Listening to very loud music or sounds

- Inserting sharp objects into the ear

- Frequent exposure to noisy environments without ear protection

Explanation: Loud sounds and physical damage can lead to ear injuries or hearing loss.

4. Following diagrams are illustrating models of musical instruments. Write the necessary things to prepare each instrument.

Answer (general):

- Drum: A drumhead (membrane), drum body (cylinder), and drumsticks.

- Guitar: Body, strings, tuning pegs, and neck.

- Flute: Tube (often metal or wood), mouthpiece, and finger holes.

Explanation: Each musical instrument requires specific parts to create sound by vibration when played.

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