10 Science Solved Sample Paper 2

Question: 12.
(1). What is fertilization?
(2). Distinguish between internal and external fertilization.
(3). What is the site of fertilization in human beings? [3]

Answer:

1. Union of male gamete with female gamete.
2. Internal: fertilisation takes place inside the female body.
   External: fertilisation takes place outside the female body.
3. Fallopian tube

Or
Describe surgical method of birth control. [3]

Answer: Tubectomy in females; Vasectomy in males

Question: 13. An object is kept in front of a concave mirror of focal length 15 cm. The image formed is three times the size of object. Calculate two possible distances of the object from the mirror. [3]

Answer: Concave mirror, f = -15 cm, h₂ = 3h₁, u = ?

Question: 14.
(1). State Snell’s law of refraction of light.
(2). A transparent medium A floats on another transparent medium B. When a ray of light travels obliquely from A into B, the refracted ray bends away from the normal. Which of these two media A or B are optically denser and why?

Hint. (1). Statement of Snell’s law; (2). Medium ‘A’ is optically denser.

Question: 15. How do harmful chemicals enter the food chain? [3]

Section D

Question: 16.
(1). With the help of a labelled diagram explain how will you refine impure copper. [5]
(2). What is anode mud?
(3). What are the important used of copper metal?
Or
(1). What is reactivity series? How does the reactivity series of metals help in predicting the relative activities of various metals?
(2). Suggest different chemical processes used for obtaining a metal from its oxides for metals in the middle of the reactivity series and metals towards the top of the reactivity series. Support your answer with one example each.