List of practice Questions

The number of terms common to two A.P.'s $3, 7, 11,..........., 407$ and $ 2, 9, 16,............,709$ is
0.16 g of dibasic acid requires 25 mL decimolar NaOH solution for complete neutralisation. The molecular mass of the acid is
A certain reaction proceeds in a sequence of three elementary steps with rate constants k1, k2 and k3. If the observed rate constant, Kobs, of the reaction is expressed as Kobs = K3 [K1/K2]1/2, then what is the observed energy of activation of the reaction?
Briefly comment on "The purpose of the author’s journey to Mount Kailash."
“A mystery I propose to explain.” What is the mystery the speaker proposes to explain?
Prove that opposite sides of a quadrilateral circumscribing a circle subtend supplementary angles at the centre of the circle.
Does Bholi enjoy her first day at school?
Here are the shadows of some 3-D objects, when seen under the lamp of an overhead projector. Identify the solid(s) that match each shadow. (There may be multiple answers for these!)
(i) A circle (ii)A square (iii)A triangle (iv)A rectangle
Justify that the following reactions are redox reactions:
  1. \(CuO(s) + H_2(g) \rightarrow Cu(s) + H_2O(g) \)
  2. \(Fe_2O_3(s) + 3CO(g) \rightarrow 2Fe(s) + 3CO_2(g) \)
  3. \(4BCl_3(g) + 3LiAlH_4(s) \rightarrow 2B_2H_6(g) + 3LiCl(s) + 3 AlCl_3 (s) \)
  4. \(2K(s) + F_2(g) \rightarrow 2K+F^- (s) \)
  5. \(4 NH_3(g) + 5 O_2(g) \rightarrow 4NO(g) + 6H_2O(g)\)
Simplify these expressions and find their values if x = 3, a = – 1, b = – 2. (i) 3x – 5 – x + 9 (ii) 2 – 8x + 4x + 4 (iii) 3a + 5 – 8a + 1 (iv) 10 – 3b – 4 – 5b (v) 2a – 2b – 4 – 5 + a
The magnetic field energy in an inductor changes from maximum value to minimum value in 5 ms, when connected to an a.c. source. The frequency of the source is

Find the number of all onto functions from the set {1,2,3,… ,n) to itself.

A sound wave travels at a speed of 339 ms–1. If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?
A survey conducted by an organization for the cause of illness and death among the women between the ages 15 - 44 (in years) worldwide, found the following figures (in %):
 
S.No. Causes Female fatality rate (%) 
1.Reproductive health conditions 

31.8 

2.Neuropsychiatric conditions  

25.4 

3.Injuries  

12.4 

4.Cardiovascular conditions   

4.3 

5.Respiratory conditions  

4.1

6.Other causes

22.0 

(i) Represent the information given above graphically. 
(ii) Which condition is the major cause of women’s ill health and death worldwide? 
(iii) Try to find out, with the help of your teacher, any two factors which play a major role in the cause in (ii) above being the major cause.

 

Boojho stands at A just on the side of a plane mirror as shown in Fig. 
Boojho stands at A just on the side of a plane mirror
Can he see himself in the mirror? Also, can he see the image of objects situated at P, Q and R?
In Ostwald's process for the manufacture of nitric acid, the first step involves the oxidation of ammonia gas by oxygen gas to give nitric oxide gas and steam. What is the maximum weight of nitric oxide that can be obtained starting only with 10.00 g. of ammonia and 20.00 g of oxygen?
List the attributes that populations but not individuals possess.
If the letters in the word TOPS can be rearranged to form a meaningful word beginning with O, the last letter of that word is your answer. If more than one such word can be formed, M is the answer and if no such word can be formed, X is the answer.
Express the following numbers in standard form:
(i) 5,00,00,000 (ii) 70,00,000 (iii) 3,18,65,00,000 (iv) 3,90,878 (v) 39087.8 (vi) 3908.78

What kind of place is Innisfree? Think about: 

(i) the three things the poet wants to do when he goes back there (stanza I); 

(ii) what he hears and sees there and its effect on him (stanza II); 

(iii) what he hears in his “heart’s core” even when he is far away from Innisfree (stanza III).

Why was Edla happy to see the gift left by the peddler?
Compare and contrast between Portia and Jessica characters in Merchant of Venice.
Directions: Fill in the blanks with the words that best fit the meaning of the sentence as a whole.
If a nation is unable to come to ______ on interpreting its own past, it will be unable to ______ its national interests.

A vertical pole of length 6 m casts a shadow 4 m long on the ground and at the same time a tower casts a shadow 28 m long. Find the height of the tower.

Express each of the following as a product of prime factors only in exponential form:
(i) 108 × 192 (ii) 270 (iii) 729 × 64 (iv) 768