CTET CTET Science 4 — Questions and Answers
Question 1: Which property of sound determines whether it is perceived as high-pitched or low-pitched?
- Amplitude
- Speed
- Frequency (Correct answer)
- Wavelength in the medium
Correct answer: Frequency
Frequency (number of vibrations per second, measured in Hz) determines pitch; higher frequency produces a higher pitch.
Question 2: What is the role of decomposers in an ecosystem?
- They convert sunlight into chemical energy
- They break down dead organic matter and recycle nutrients (Correct answer)
- They transfer energy from plants to animals
- They produce oxygen through respiration
Correct answer: They break down dead organic matter and recycle nutrients
Decomposers like fungi and bacteria break down dead organisms into simpler substances, returning nutrients to the soil for reuse.
Question 3: A student finds that a substance turns blue litmus red and has a pH of 3. This substance is best described as:
- A strong base
- A weak acid
- A strong acid (Correct answer)
- A neutral substance
Correct answer: A strong acid
A pH of 3 indicates a strong acid; such substances turn blue litmus red and have a large concentration of hydrogen ions.
Question 4: Which type of blood vessel carries oxygenated blood away from the heart to the body?
- Veins
- Capillaries
- Arteries (Correct answer)
- Venules
Correct answer: Arteries
Arteries carry oxygenated blood (except the pulmonary artery) away from the heart to various organs and tissues of the body.
Question 5: What is the purpose of the control variable in a scientific experiment?
- To be changed by the experimenter to observe results
- To be measured as the outcome of the experiment
- To remain constant so that only one variable affects the outcome (Correct answer)
- To represent the hypothesis being tested
Correct answer: To remain constant so that only one variable affects the outcome
Control variables are kept constant so they do not influence the result, ensuring that only the independent variable affects the dependent variable.
Question 6: Which layer of the Earth's atmosphere contains the ozone layer that absorbs harmful UV radiation?
- Troposphere
- Mesosphere
- Stratosphere (Correct answer)
- Thermosphere
Correct answer: Stratosphere
The ozone layer is located in the stratosphere, approximately 15–35 km above Earth's surface, where it absorbs most of the Sun's ultraviolet radiation.
Question 7: In science education for upper primary classes, using everyday examples like bicycles to teach force and motion is effective because it:
- Reduces the need for laboratory experiments
- Connects abstract concepts to students' prior experiences (Correct answer)
- Simplifies complex formulas into easier ones
- Avoids the use of scientific terminology
Correct answer: Connects abstract concepts to students' prior experiences
Anchoring abstract science concepts to familiar real-world objects activates prior knowledge and makes new concepts meaningful and easier to understand.
CTET CTET Science 4
Which property of sound determines whether it is perceived as high-pitched or low-pitched?