List of practice Questions

What was Valli’s deepest desire? Find the words and phrases in the story that tell you this.
What shows her concern for the environment?
What kind of teachers did Margie and Tommy have?
For the wave described in Exercise 14.8, plot the displacement (y) versus (t) graphs for x = 0, 2 and 4 cm. What are the shapes of these graphs? In which aspects does the oscillatory motion in travelling wave differ from one point to another: amplitude, frequency or phase ?
What is the perimeter of each of the following figures? What do you infer from the answers?
List of figures
What is the importance of universal law of gravitation?
What is Johnsy’s illness? What can cure her, the medicine or the willingness to live?
What is Behrman’s masterpiece? What makes Sue say so?
What impression would you form of a state where the King was ‘just and placid’?
What guesses are made by Think–Tank about the books found on earth?
Make an oblique sketch for each one of the given isometric shapes:
isometric shapes
What does Anne write in her first essay?
Mention three ways in which the author’s grandmother spent her days after he grew up.
Mother wants to divide ₹ 36 between her daughters Shreya and Bhoomika in the ratio of their ages. If age of Shreya is 15 years and age of Bhoomika is 12 years, find how much Shreya and Bhoomika will get.
What cross-sections do you get when you give a
(i) vertical cut (ii) horizontal cut to the following solids?
(a) A brick (b) A round apple (c) A die (d) A circular pipe (e) An ice cream cone
What are transgenic bacteria? Illustrate using any one example.
What are the differences between the transport of materials in xylem and phloem?

Using the property of determinants and without expanding, prove that: \(\begin{vmatrix}a-b&b-c&c-a\\b-c&c-a&a-b\\c-a&a-b&b-c\end{vmatrix}\)=0

Two circles of radii 5 cm and 3 cm intersect at two points and the distance between their centres is 4 cm. Find the length of the common chord.
In Fig. 10.13, XY and X'Y' are two parallel tangents to a circle with centre O and another tangent AB with point of contact C intersecting XY at A and X'Y' at B. Prove that ∠AOB = 90°.
XY and X'Y' are two parallel tangents to a circle with centre O
Fig. 10.13
In a class of 60 students, 30 opted for NCC, 32 opted for NSS and 24 opted for both NCC and NSS. If one of these students is selected at random, find the probability that
(i)The student opted for NCC or NSS.
(ii)The student has opted neither NCC nor NSS.
(iii)The student has opted NSS but not NCC
Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.
Two bodies of masses 10 kg and 20 kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. A horizontal force F = 600 N is applied to
  1. A
  2. B along the direction of string. What is the tension in the string in each case?
Two bodies of masses 10 kg and 20 kg respectively
The weight of 72 books is 9 kg. What is the weight of 40 such books?
$1.5\, g$ of a non-volatile, non-electrolyte is dissolved in $50 \,g$ benzene $(K_b\, =\, 2.5\, K kg \,mol^{-1}$ ). The elevation of the boiling point of the solution is $0.75\, K$. The molecular weight of the solute in $g$ $mol^{-1}$ is