CBSE Class 10 Science Competency-Based MCQs
CBSE Class 10 Science Competency-Based MCQs
Class: 10 | Subject: Science
Section: Exam Oriented
Topic: Competency-Based MCQs
Board: CBSE Board Examination
Section: Exam Oriented
Topic: Competency-Based MCQs
Board: CBSE Board Examination
Instructions: These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 10 Science Board Examination standard.
1. A student observed that magnesium ribbon burns with a dazzling flame. This indicates:
Answer: C
Burning magnesium is a chemical reaction producing magnesium oxide with release of heat and light, hence exothermic.
Burning magnesium is a chemical reaction producing magnesium oxide with release of heat and light, hence exothermic.
2. Resistance of a wire depends on:
Answer: C
R = ρL/A → Resistance depends on resistivity (material), length and cross-sectional area.
R = ρL/A → Resistance depends on resistivity (material), length and cross-sectional area.
3. The functional unit of kidney is:
Answer: B
Nephron filters blood, reabsorbs useful substances and forms urine.
Nephron filters blood, reabsorbs useful substances and forms urine.
4. Image formed by a plane mirror is:
Answer: B
Plane mirrors always form virtual, erect images of same size.
Plane mirrors always form virtual, erect images of same size.
5. Which gas turns lime water milky?
Answer: C
CO₂ reacts with Ca(OH)₂ forming CaCO₃ (milky precipitate).
CO₂ reacts with Ca(OH)₂ forming CaCO₃ (milky precipitate).
6. Mendel’s law of segregation states that:
Answer: B
Allele pairs segregate so each gamete gets one allele.
Allele pairs segregate so each gamete gets one allele.
7. pH of acidic solution is:
Answer: C
Acids release H⁺ ions → pH less than 7.
Acids release H⁺ ions → pH less than 7.
8. SI unit of power is:
Answer: B
1 Watt = 1 Joule/second.
1 Watt = 1 Joule/second.
9. Ozone layer protects from:
Answer: B
Ozone absorbs harmful ultraviolet radiation.
Ozone absorbs harmful ultraviolet radiation.
10. Concave mirror is used in headlights because it:
Answer: A
Source at focus → reflected rays become parallel.
Source at focus → reflected rays become parallel.
11. Rusting requires:
Answer: C
Both oxygen and water are essential for rusting.
Both oxygen and water are essential for rusting.
12. Unit of electric current:
Answer: B
Ampere measures rate of charge flow.
Ampere measures rate of charge flow.
13. Photosynthesis occurs in:
Answer: C
Chloroplast contains chlorophyll for photosynthesis.
Chloroplast contains chlorophyll for photosynthesis.
14. Human male gamete is:
Answer: B
Sperm fertilizes ovum.
Sperm fertilizes ovum.
15. Alloy of iron:
Answer: B
Steel = Iron + Carbon.
Steel = Iron + Carbon.
16. Convex lens forms real image when object is:
Answer: B
Object beyond F → real inverted image.
Object beyond F → real inverted image.
17. Largest artery:
Answer: B
Aorta carries oxygenated blood from heart.
Aorta carries oxygenated blood from heart.
18. Energy stored in food is measured in:
Answer: C
Food energy is expressed in calories.
Food energy is expressed in calories.
19. Non-renewable resource:
Answer: C
Coal takes millions of years to form.
Coal takes millions of years to form.
20. Magnetic field is strongest at:
Answer: B
Magnetic lines are densest at poles.
Magnetic lines are densest at poles.