Notes

Section A: Multiple Choice Questions (MCQs) (20 marks)

1. The colored part of the human eye which controls the amount of light entering the eye is:
a) Retina
b) Pupil
c) Iris
d) Cornea

2. The phenomenon that causes the sky to appear blue is:
a) Dispersion
b) Scattering
c) Reflection
d) Refraction

3. The region of the human eye that is sensitive to light and responsible for vision is the:
a) Pupil
b) Retina
c) Cornea
d) Iris

4. The defect of vision where distant objects are not clearly seen is:
a) Myopia
b) Hypermetropia
c) Presbyopia
d) Astigmatism

5. The phenomenon that explains the formation of a rainbow is:
a) Refraction
b) Reflection
c) Dispersion
d) Scattering

6. Which of the following is a good conductor of electricity?
a) Wood
b) Rubber
c) Copper
d) Plastic

7. The SI unit of electric current is:
a) Volt
b) Ampere
c) Ohm
d) Coulomb

8. The device used to break or complete an electric circuit is called:
a) Ammeter
b) Voltmeter
c) Switch
d) Resistor

9. In a parallel circuit, the voltage across each component is:
a) Different
b) Same
c) Variable
d) Zero

10. A fuse wire is made of:
a) Copper
b) Aluminum
c) Lead
d) Silver


11. Which of the following is a non-metal?
a) Iron
b) Oxygen
c) Copper
d) Silver

12. The metal which exists in a liquid state at room temperature is:
a) Mercury
b) Silver
c) Gold
d) Copper

13. The property of metals to be drawn into wires is known as:
a) Ductility
b) Malleability
c) Conductivity
d) Reactivity

14. Which of the following metals is the best conductor of electricity?
a) Copper
b) Aluminum
c) Iron
d) Lead

15. Non-metals generally have ____ melting and boiling points.
a) High
b) Low
c) Variable
d) No specific pattern

16. Which of the following substances is an acid?
a) Baking soda
b) Vinegar
c) Ammonia
d) Milk

17. The pH scale measures the:
a) Acidity or basicity of a substance
b) Temperature of a substance
c) Density of a substance
d) Color of a substance

18. The chemical formula for Nitric acid is:
a) H2SO4
b) HCl
c) HNO3
d) H2CO3

19. A substance that turns blue litmus paper red is:
a) Acid
b) Base
c) Neutral
d) Salt

20. Which of the following is a strong base?
a) Sodium hydroxide (NaOH)
b) Ammonium hydroxide (NH4OH)
c) Potassium hydroxide (KOH)
d) Calcium hydroxide (Ca(OH)2)



Section-B


1. Explain the structure and function of the human eye along with diagram. (5 m)

2. Explain how a person suffering from myopia can correct their vision using a concave lens. Explain with diagram. (4 marks)

3. What is the cause of the red color of the Sun during sunrise and sunset? (1 m)


4. Discuss the formation and characteristics of an image formed by a concave lens. (2 m)



5. Explain the correction of hypermetropia using a convex lens and draw ray diagrams to illustrate the same. (5 m)



6. Explain the difference between a conductor and an insulator, giving examples of each. (3 m)

7. Describe 3 factors affecting the resistance of a conductor.(3 m)

8. State Ohm's Law. (2 m)


9. Discuss the advantages and disadvantages of using parallel and series circuits in household wiring.(3 m)


10. Discuss 3 safety measures to be followed while handling electrical appliances and wiring. (2 m)

11. A 10 Ω resistor is connected across a 12 V battery. Calculate the electric current passing through the resistor. (1 m)


12. Explain the terms 'malleability' and 'ductility' with suitable examples.(3 m)

13. Discuss 3 lines about reactivity series of metals and its significance in predicting reactions. (3 m)

14. Differentiate between metals and non-metals based on their physical properties. (4 m)

15. Explain the process of corrosion of metals, its causes, and how it can be prevented. (2 m)


16. Discuss the extraction of any 1 metal from their ores with the help of relevant chemical reactions. (3 m)

17. Describe the chemical properties of acids and bases with respect to their reactions with metals
OR
Write 4 reactions of acids and bases with metals. (4 m)

18. A metal 'X' displaces 'Y' from its salt solution. Write the chemical reaction involved and the type of reaction. (2 m)


19. Discuss the differences between acids and bases based on their chemical properties. (4 m)

20. Write the chemical names and formulas of three common salts and their uses. (3 m)

21. Describe the pH scale and its significance in characterizing acids and bases. (2 m)


22. Explain 4 uses of acids in our daily life, giving examples. (2 m)

23. Discuss the reaction of metals with acids, giving 2 suitable examples and chemical equations. (2 m)


24. Describe the different methods of asexual reproduction in plants with suitable examples and diagram. (5 m)