Central Institute of Higher Tibetan Studies 2009 CBSE CLASS X - Question Paper

(iii) is the pH value of baking soda solution lesser than or greater than 7?
14. A concave mirror produces 3 times enlarged image of an object placed at 10 cm
infront of it. compute the radius of curvature of the mirror.
15. a) What were the 2 major shortcomings of Mendeleev’s periodic table? How have
these been removed in the modern periodic table?
b) 2 elements X and Y have atomic numbers 12 and 16 respectively. Write the
electronic configuration for these elements. To which period of the modern periodic
table do these 2 elements belong? What kind of bond will be formed ranging from
them and why?
OR
a) What were the 2 achievements of Mendeleev’s Periodic table? What was the
basis of classification of elements in it ?
b) An element X (2,8,2) combines separately with NO3 and (SO4)2 -, (PO4)3 - radicals.
Write the formulae of the 3 compounds so formed. To which group of the periodic
table does the element ‘X’ belong? Will it form covalent or ionic compound? Why?
16. a) The electric power consumed by a device may be computed by using either of the
two expressions P = I2R or P = V 2. The 1st expression shows that it is directly
R
proportional to R whereas the 2nd expression shows inverse proportionality.
How can the seemingly various dependence of P on R in these expressions be
explained?
b) discuss the following:
(i) Why is tungsten used almost exclusively for filament of electric lamps?
(ii) Why are copper and aluminium wires usually used for electricity transmission?
OR
discuss the meaning of the word ‘electromagnetic’ and ‘induction’ in the term
electromagnetic induction. On what factors does the value of induced current produced in
a circuit depend? Name and state the rule used for determination of direction of induced
current. State 1 practical application of this phenomenon in everyday life.
part B
17. From the list provided below, pick out the items which can be recycled:-
Used clothes, polythene carry bags, glass bottles, newsprint 1
320
18. What does the provided experimental
set-up domonstrate? 1
19. A particular hormone requires lodine for its synthesis. Name the endocrine gland which
secretes this hormone and state its location in the human body. 1
20. Why are many thermal power plants set up near coal or oilfields? 2

Earning:   Approval pending.