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Question (11)

QN0031878

Which of the following correctly explains why a pinwheel rotates when you blow air on it?

(A) Air changes into electricity.
(B) Wind energy is converted into movement.
(C) The pinwheel produces heat energy.
(D) The paper becomes lighter in air.

Correct Answer: B

Explanation:

Moving air transfers energy to the pinwheel, making it rotate.

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Question (12)

QN0031879

A teacher asks four students to identify a clean source of energy. Student P says coal, Student Q says wind, Student R says diesel and Student S says firewood. Who has identified a clean source of energy?

(A) Student P
(B) Student Q
(C) Student R
(D) Student S

Correct Answer: B

Explanation:

Wind is a clean source of energy because it does not produce smoke while generating electricity.

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Question (13)

QN0031880

Four families use different methods to dry washed clothes. Family A dries them indoors, Family B dries them under direct sunlight, Family C keeps them inside a closed room and Family D keeps them in a damp basement. Which family is most likely to dry the clothes the fastest?

(A) Family A
(B) Family B
(C) Family C
(D) Family D

Correct Answer: B

Explanation:

Sunlight provides heat that speeds up the evaporation of water.

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Question (14)

QN0031881

Which sequence correctly shows the flow of energy?

(A) Petrol → Human body → Running
(B) Food → Human body → Running
(C) Wind → Human body → Running
(D) Electricity → Human body → Running

Correct Answer: B

Explanation:

Humans obtain energy from food to perform physical activities.

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Question (15)

QN0031882

A village wants to reduce air pollution while generating electricity. Which option should it choose?

(A) Build more coal-fired power plants.
(B) Burn more wood every day.
(C) Install solar panels and windmills.
(D) Increase the use of diesel generators.

Correct Answer: C

Explanation:

Solar and wind energy generate electricity without producing air pollution.

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Question (16)

QN0031883

A student matches each activity with its energy source: Water wheel spinning → Flowing water, Car moving → Petrol, Child writing → Food, Electric iron heating → Wind. Which matching is incorrect?

(A) 1 only
(B) 2 only
(C) 4 only
(D) 3 only

Correct Answer: C

Explanation:

An electric iron works using electricity, not wind.

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Question (17)

QN0031884

A classroom has four LED bulbs, three fans and one projector switched on unnecessarily during recess. What is the best way to save energy?

(A) Open all windows and keep everything running.
(B) Switch off the unused electrical appliances.
(C) Add more bulbs to increase brightness.
(D) Keep the appliances on throughout the day.

Correct Answer: B

Explanation:

Switching off unused electrical appliances reduces electricity consumption.

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Question (18)

QN0031885

Which of the following best explains why the Sun is called the main source of energy for life on Earth?

(A) It only helps vehicles move.
(B) It provides light and heat that support life and many natural processes.
(C) It directly supplies petrol and diesel.
(D) It produces electricity in every house automatically.

Correct Answer: B

Explanation:

The Sun provides light and heat essential for life and many natural processes.

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Question (19)

QN0031886

Read the statements: I. Batteries contain stored energy. II. Our body can store energy for future use. III. Electricity can be stored only in fans. Which statements are correct?

(A) I only
(B) II only
(C) I and II only
(D) I, II and III

Correct Answer: C

Explanation:

Batteries and our body store energy, but fans do not store electricity.

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Question (20)

QN0031887

A student prepares the following energy chain: Sun → Solar panel → Electricity → LED bulb → Light. Which conclusion is correct?

(A) Electricity is produced from sunlight using a solar panel.
(B) The LED bulb produces sunlight.
(C) Solar panels work only at night.
(D) The Sun receives electricity from the LED bulb.

Correct Answer: A

Explanation:

Solar panels convert sunlight into electricity, which powers the LED bulb.

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Question (11)

Which of the following correctly explains why a pinwheel rotates when you blow air on it?

Explanation:

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Question (12)

A teacher asks four students to identify a clean source of energy. Student P says coal, Student Q says wind, Student R says diesel and Student S says firewood. Who has identified a clean source of energy?

Explanation:

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Question (13)

Four families use different methods to dry washed clothes. Family A dries them indoors, Family B dries them under direct sunlight, Family C keeps them inside a closed room and Family D keeps them in a damp basement. Which family is most likely to dry the clothes the fastest?

Explanation:

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Question (14)

Which sequence correctly shows the flow of energy?

Explanation:

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Question (15)

A village wants to reduce air pollution while generating electricity. Which option should it choose?

Explanation:

Link:

Question (16)

A student matches each activity with its energy source: Water wheel spinning → Flowing water, Car moving → Petrol, Child writing → Food, Electric iron heating → Wind. Which matching is incorrect?

Explanation:

Link:

Question (17)

A classroom has four LED bulbs, three fans and one projector switched on unnecessarily during recess. What is the best way to save energy?

Explanation:

Link:

Question (18)

Which of the following best explains why the Sun is called the main source of energy for life on Earth?

Explanation:

Link:

Question (19)

Read the statements: I. Batteries contain stored energy. II. Our body can store energy for future use. III. Electricity can be stored only in fans. Which statements are correct?

Explanation:

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Question (20)

A student prepares the following energy chain: Sun → Solar panel → Electricity → LED bulb → Light. Which conclusion is correct?

Explanation:

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