CTET CTET Science 3 — Questions and Answers
Question 1: A teacher asks students why a thick glass tumbler cracks when boiling water is poured into it. The best scientific explanation is:
- Glass is soluble in hot water
- Uneven thermal expansion causes stress in the glass (Correct answer)
- Boiling water has higher pressure that breaks glass
- Glass cannot conduct heat at all
Correct answer: Uneven thermal expansion causes stress in the glass
The inner surface of thick glass expands quickly while the outer surface remains cool, creating uneven thermal stress that cracks it.
Question 2: Which type of rock is formed from the cooling and solidification of magma or lava?
- Sedimentary rock
- Metamorphic rock
- Igneous rock (Correct answer)
- Limestone
Correct answer: Igneous rock
Igneous rocks form when molten magma (underground) or lava (on the surface) cools and solidifies.
Question 3: What is the main cause of seasons on Earth?
- Earth's varying distance from the Sun
- Earth's axial tilt of 23.5 degrees (Correct answer)
- The Moon's gravitational pull
- Differences in Earth's orbital speed
Correct answer: Earth's axial tilt of 23.5 degrees
Earth's axial tilt of 23.5° causes different hemispheres to receive varying amounts of sunlight throughout the year, creating seasons.
Question 4: Which microorganism is responsible for the fermentation of milk into curd (yogurt)?
- Yeast
- Rhizobium
- Lactobacillus (Correct answer)
- Penicillium
Correct answer: Lactobacillus
Lactobacillus bacteria ferment lactose in milk into lactic acid, which causes the milk to curdle and form yogurt.
Question 5: An object placed beyond the center of curvature (2F) of a convex lens forms an image that is:
- Virtual, erect, and enlarged
- Real, inverted, and diminished (Correct answer)
- Real, erect, and same size
- Virtual, inverted, and diminished
Correct answer: Real, inverted, and diminished
When an object is placed beyond 2F of a convex lens, the image formed is real, inverted, and diminished (smaller than the object).
Question 6: Which nutrient is most important for the growth and repair of body tissues?
- Carbohydrates
- Fats
- Proteins (Correct answer)
- Vitamins
Correct answer: Proteins
Proteins are the building blocks of the body and are essential for growth, repair, and maintenance of all body tissues.
Question 7: In the context of teaching science, what does 'inquiry-based learning' primarily emphasize?
- Memorizing scientific facts and formulas
- Students asking questions and discovering answers through investigation (Correct answer)
- Teacher demonstrating experiments for students to observe
- Reading textbooks and answering comprehension questions
Correct answer: Students asking questions and discovering answers through investigation
Inquiry-based learning centers on students posing questions, designing investigations, and constructing knowledge through their own exploration.
CTET CTET Science 3
A teacher asks students why a thick glass tumbler cracks when boiling water is poured into it.
The best scientific explanation is: