X SCIENCE SA II - 1 & 2 MARKS QUESTIONS SAMPLE PAPER 2

1.          What  is the nature of the image  formed at retina  of human eye ?

2.          Why  do Carbon compounds not  conduct electricity ?

3.          What  is meant by biological  Magnification ?

4.          Why do food  chains  generally consists  of only three  to four  trophic levels.

5.          Why  do stars  seem  higher  than  they  actually are ?

6.          An  object  3 cm  high  is placed at  a distance of 8 cm  from  a concave  mirror which produces a virtual image  4.5 cm high  . What  is the  focal length  of the  mirror ?  Also find  the position of the image.

7.          A beam  of white  light falling on a glass prism  gets split up into 7 colours  marked 1 to 7 as shown in the diagram. A student makes  the following statement about  the spectrum observed on the screen  - The colours  at position 3 and  5 are  similar  to the  colour  of the  sky  and  the  core  of a hard boiled  egg respectively. Is the statement made by the student correct  or incorrect ? Justify.

8.          What are fossil fuels ? ” Burning of fossil fuels leads to acid rains”.  Justify this statement.

9.          The following table shows  elements represented by the letters  A , B , C , D , E , E , F , G, and  H.

Group        1        2        13      14       15     16       17     18

Element       A       B       C       D       E       F        G       H

(i)      Which  of the elements has  the atomic  size

(a)     biggest  and           (b)     smallest ?

(ii)     Which  element has  valency (a) 3 and  (b) zero  ?

10.       How  does  (a) metallic  character and  (b) atomic  size vary

(i) in a group and           (ii) a  period ?

11.       Forests  are ’ biodiversity hotspots’. Justify this statement.

12.       Explain  how the ovary function both as the reproductive organs as well as the endocrine glands ?

13.       How  does  bread mould reproduce ? Draw   a  diagram showing this  mode   of reproduction.

14.       (a)     What  happens when a ray  of light  strikes  the  surface  of separation between the two  media at right  angle  ?

(b)     Light enters  from air into diamond which  has a refractive index  of 2.42. Calculate the speed of light  in diamond. The speed of light  in air is 3 x10⁸ m/s.

15.       Name  those  parts  of a flower  which  serve  the same  function as the following do in the   animal  :-

(i)      Testis           (ii)     Ovary          (iii)    Eggs            (iv) Sperms