Grade 6 Science Answer key for the multiple-choice questions in Part I, Part II along with the correct answer and explanations for each question:

### 1. A characteristic common to all animals

- Answer: 3. Absence of chlorophyll

- Explanation: Animals lack chlorophyll, which is found in plants for photosynthesis.

### 2. The process only plants can perform

- Answer: 2. Release of oxygen by gaining carbon dioxide

- Explanation: Only plants release oxygen through photosynthesis, using carbon dioxide.

### 3. Select the thing that occupies space

- Answer: 1. Air

- Explanation: Air, unlike light, heat, or sound, is a gas that occupies space.

### 4. Correct order of A, B, and C in the water cycle

- Answer: 3. Precipitation, Surface water, Groundwater

- Explanation: Precipitation falls, forming surface water that infiltrates to become groundwater.

### 5. Based on salinity, which has the least dissolved salt?

- Answer: 3. Freshwater

- Explanation: Freshwater has lower salinity than marine, brackish, or muddy water.

### 6. Not a natural sound

- Answer: 3. Sound of a horn

- Explanation: A horn is artificial; sounds of birds, waterfalls, and wind are natural.

### 7. Most suitable energy source for a hilltop

- Answer: 1. Wind

- Explanation: Wind is a renewable energy source ideal for hilltops due to high wind speeds.

### 8. Fossil fuel in gaseous state

- Answer: 1. LP gas

- Explanation: Liquefied petroleum gas is a gaseous fossil fuel, unlike solid (coal) or liquid (petrol).

### 9. Conclusion from the setup for vision

- Answer: 2. Light is needed for vision

- Explanation: Vision requires light to see objects.

### 10. Non-luminous object

- Answer: 2. Moon

- Explanation: The moon reflects light from the sun; it doesn’t produce light.

### 11. Pie chart: water in seas vs. consumable water

- Answer: 3. A and C

- Explanation: Seas represent the largest water source, while consumable water is a much smaller portion.

### 12. Standard International unit for temperature

- Answer: 1. Kelvin

- Explanation: Kelvin is the SI unit for measuring temperature.

### 13. Factor from soil used in photosynthesis

- Answer: 3. Water

- Explanation: Plants absorb water from soil for photosynthesis.

### 14. Correct statement about sound

- Answer: 4. Sound is produced by vibrations

- Explanation: Sound waves are generated by the vibration of objects.

### 15. Substance separable with a magnet

- Answer: 3. Steel filings

- Explanation: Steel is magnetic, unlike brass, aluminum, or copper.

### 16. Instrument with a pivoted magnet that moves freely

- Answer: 3. Compass

- Explanation: A compass has a pivoted magnet that aligns with Earth's magnetic field.

### 17. Correct type of chemical cell and example

- Answer: 1. Primary cell - Dry cell

- Explanation: Dry cells are primary cells, not rechargeable like secondary cells.

### 18. Symbols in the circuit for A, B, C

- Answer: 1. Ammeter, Bulb, Dry cell

- Explanation: An ammeter measures current, a bulb represents light, and a dry cell supplies power.

### 19. Observation for wire around pencil connected to cells

- Answer: 2. Heating of the wire

- Explanation: The electric current heats the wire due to resistance.

### 20. Use of heat from rubbing

- Answer: 2. Lighting a matchstick

- Explanation: Striking a match creates friction and ignites the match.

### 21. Effect of Earth's rising temperature

- Answer: 1. Melting of glaciers

- Explanation: Global warming causes glaciers to melt, affecting sea levels.

### 22. When expansion knowledge is not useful

- Answer: 4. Making an iron gate

- Explanation: Expansion principles apply to loosening lids, fixing rims, and rail installation, not gate-making.

### 23. Organisms that produce food for all life

- Answer: 1. Green plants

- Explanation: Green plants, as producers, make food through photosynthesis.

### 24. Correct statement about the food chain

- Answer: 3. Solar energy is transferred through a food chain

- Explanation: Solar energy enters the food chain through plants and flows to other organisms.

### 25. Speed of anemometer if 20 turns in 4 minutes

- Answer: 1. 20/4 turns per minute (5 turns per minute)

- Explanation: The speed is calculated as 20 divided by 4, giving 5 turns per minute.

Here’s a detailed list of questions and suggested answers for Part II of the Grade 6 Science test. Each question is followed by a structured answer and explanation where relevant.

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### Question 1: Experimental Setups and Observations

#### (A) Observing Galvanometer Response

- Activity (i): Allow the bar magnet to fall through the plastic tube.

- Observation: No deflection in the galvanometer.

- Activity (ii): Insert the magnet into the tube, close both ends with hands, and move the tube back and forth.

- Observation: Slight deflection in the galvanometer, indicating current induction due to movement.

#### (B) Simple Cell Setup Observations

- (i) Name X solution and Y strip respectively.

- Answer: X is an electrolyte solution (commonly dilute sulfuric acid); Y is a zinc strip.

- (ii) Observations near the Zinc sheet and Y strip.

- Answer: Bubbles appear near the zinc sheet, showing gas release, while slight corrosion occurs.

- (iii) Observation of the bulb after a few minutes.

- Answer: The bulb dims as the battery charge decreases.

#### (C) Circuit Diagram with Two Dry Cells and an LED

- (i) Draw a circuit diagram using standard symbols.

- Answer: [Provide a diagram showing two dry cells, an LED, and a switch in series.]

- (ii) Physical properties of O and P in the switch.

- Answer: O is a conductor (metallic), and P is an insulator (plastic or rubber).

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### Question 2: Temperature Experiment and Wind Vane Observations

#### (A) Increase of Temperature in a Laboratory Setup

- (i) Observation on thermometer when a spirit lamp is placed under the beaker.

- Answer: Temperature reading increases as heat transfers to the water.

- (ii) Thermometer reading when water starts to boil.

- Answer: 100°C (assuming standard atmospheric pressure).

- (iii) Change in state of water as it boils.

- Answer: Water transitions from liquid to gas (steam).

- (iv) Type of energy transferred from the spirit lamp to water.

- Answer: Heat energy.

- (v) Place where liquid expansion occurs.

- Answer: In the water inside the beaker as it heats up.

#### (B) Wind Vane Setup

- (i) Direction of wind based on wind vane.

- Answer: Points in the direction where the arrow is facing.

- (ii) Four raw materials to prepare a wind vane.

- Answer: Cardboard, metal rod, plastic sheet, and a needle.

- (iii) Definition of humidity.

- Answer: Humidity is the amount of water vapor present in the air.

- (iv) Natural disaster from pressure depression and high-speed air movement.

- Answer: Cyclone or hurricane.

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### Question 3: Food Web and Nature Diary Observations

#### (A) Food Web

- (i) Two herbivorous animals in the food web.

- Answer: Rabbit and caterpillar.

- (ii) A food chain with three links from the food web.

- Answer: Grass → Caterpillar → Frog.

- (iii) Organisms directly affected if caterpillars and grasshoppers are removed.

- Answer: Frogs and birds, as they rely on these for food.

- (iv) Name the process of food production in grass.

- Answer: Photosynthesis.

#### (B) Nature Diary Observations

- (i) Days observing movement of organisms.

- Answer: Tuesday, Wednesday, Thursday.

- (ii) Conclusion from Monday’s observation.

- Answer: Exhaled air contains carbon dioxide, turning lime water milky.

- (iii) Characteristic related to Thursday’s observation.

- Answer: Breathing (indicating respiration).

- (iv) Two plants that show sleeping movements at night.

- Answer: Mimosa (touch-me-not) and Albizia (silk tree).

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### Question 4: Magnetism and Sound

#### (A) Electromagnets and Bar Magnet Properties

- (i) Select substances suitable for an electromagnet.

- Answer: Piece of iron and copper wire.

- (ii) Locations on a bar magnet that attract the most pins.

- Answer: Ends labeled 1 and 3.

- (iii) What are these places called?

- Answer: Magnetic poles.

- (iv) Naming of ends when compass’s N end is attracted to 3rd end of magnet.

- Answer: End 1 is North, end 3 is South.

#### (B) Types of Sound

- (i) Two artificial sounds from the list.

- Answer: Sound of a tractor, sound of a vehicle horn.

- (ii) Example of music and noise from the list.

- Answer: Music: Sound of a guitar; Noise: Sound of a tractor.

- (iii) Explanation of noise.

- Answer: Noise is an unwanted or unpleasant sound.

- (iv) Changes to produce different sounds in an instrument using a rubber membrane.

- Answer: Tightening or loosening the membrane.

- (v) Similar musical instrument.

- Answer: Drum.

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### Question 5: Energy Sources and Farmer's Setup

#### (A) Energy Sources

- (i) Main source of energy.

- Answer: Sun.

- (ii) Two examples of fossil fuels.

- Answer: Coal, petroleum.

- (iii) Source of energy for drying clothes and removing rice grain.

- Answer: Sunlight.

- (iv) Two examples of biomass used at home.

- Answer: Firewood, animal dung.

#### (B) Farmer’s Animal Deterrent Setup

- (i) Type of energy used in the setup.

- Answer: Mechanical energy.

- (ii) Type of energy produced by the setup.

- Answer: Sound energy.

- (iii) Two improvements for efficiency.

- Answer: Use stronger materials, increase length of the rod for better movement.

- (iv) Suitable location for setup: paddy field or home garden?

- Answer: Paddy field.

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### Question 6: Properties of Light and Observing Light

#### (A) Observing Light through a Tube

- (i) Eye that can observe the light spot clearly, A or B?

- Answer: Eye A (assuming A is aligned with the hole and tube).

- (ii) Property of light observed.

- Answer: Light travels in a straight line.

- (iii) Energy source and type.

- Answer: Energy source: Battery; Energy type: Electrical energy converted to light.

- (iv) Name X and Y.

- Answer: X: Source of light (e.g., bulb); Y: Cardboard with hole.

- (v) Property of the wall that prevents light from passing.

- Answer: Opaqueness.

- (vi) Two luminous objects.

- Answer: Sun, light bulb.

- (vii) Strategies to observe A and B light ray clearly.

- Answer: Use a straight tube, increase brightness of the light source.

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### Question 7: Properties of Matter

#### (A) Classification of Matter

- Fill in the blanks:

- (i) Non-matter.

- (ii) Solid.

- (iii) Gases.

#### (B) Characteristics of Solids

- (i) Property in a balloon.

- Answer: Elasticity.

- (ii) Definition of malleability.

- Answer: Ability to be hammered into thin sheets without breaking.

- (iii) Two brittle substances.

- Answer: Glass, ceramic.

- (iv) Property allowing substances to be drawn into wires.

- Answer: Ductility.

- (v) Substance with smooth texture.

- Answer: Silk.

- (vi) Characteristic present in gas but not in liquid.

- Answer: Compressibility.

- (vii) Physical state of water.

- Answer: Liquid (at room temperature).

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This covers all questions and answers for Part II, along with the explanations.

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