List of top Questions asked in CBSE Class X

The water of crystallization is present in:
(i) Bleaching Powder
(ii) Plaster of Paris
(iii) Washing Soda
(iv) Baking Soda
Juice of tamarind turns blue litmus to red. It is because of the presence of a chemical compound called:
In which one of the following situations a chemical reaction does not occur?
In order to prepare dry hydrogen chloride gas in a humid atmosphere, the gas produced is passed through a guard tube (drying tube) which contains:
Assertion (A): Concentrated nitric acid is diluted by adding water slowly to acid with constant stirring.
Reason (R): Concentrated nitric acid is easily soluble in water.
In the light of the above statements, choose the most appropriate answer from the options given below:
Example of thermal decomposition reaction are:
  1. \( \text{2AgCl} \rightarrow \text{2Ag} + \text{Cl}_2 \)
  2. \( \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \)
  3. \( \text{2H}_2\text{O} \rightarrow \text{2H}_2 + \text{O}_2 \)
  4. \( \text{2KClO}_3 \rightarrow \text{2KCl} + \text{3O}_2 \)
The colour of the solution observed after about 1 hour of placing iron nails in copper sulphate solution is:

Select from the following a statement which is not true about the burning of magnesium ribbon in air:

The colour of the solution observed after about 1 hour of placing iron nails in copper sulphate solution is: 

If the zeroes of the polynomial $ax^2 + bx + \dfrac{2a}{b}$ are reciprocal of each other, then the value of $b$ is
In the given graph, the polynomial \(p(x)\) is shown. Number of zeroes of \(p(x)\) is
polynomial p(x)

In the given figure, graph of polynomial \(p(x)\) is shown. Number of zeroes of \(p(x)\) is

If $\dfrac{2\tan30^\circ}{1+\tan^2 30^\circ} = \dfrac{2\tan30^\circ}{\sqrt{1 - \tan^2 30^\circ}}$, then $x : y =$
A peacock sitting on the top of a tree of height 10 m observes a snake moving on the ground. If the snake is $10\sqrt{3}$ m away from the base of the tree, then angle of depression of the snake from the eye of the peacock is
In a right triangle ABC, right-angled at A, if $\sin B = \dfrac{1}{4}$, then the value of $\sec B$ is
If \(\sin \theta = \frac{1}{9}\), then \(\tan \theta\) is equal to
If \(x = \cos 30^\circ - \sin 30^\circ\) and \(y = \tan 60^\circ - \cot 60^\circ\), then
If the length of the shadow of a tower is \(\sqrt{3}\) times its height, then the angle of elevation of the sun is
If \(\sqrt{3} \sin \theta = \cos \theta\), then value of \(\theta\) is
In \(\triangle ABC, \angle B = 90^\circ\). If \(\frac{AB}{AC} = \frac{1}{2}\), then \(\cos C\) is equal to

Given $\triangle ABC \sim \triangle PQR$, $\angle A = 30^\circ$ and $\angle Q = 90^\circ$. The value of $(\angle R + \angle B)$ is

The distance of point \((a, -b)\) from the \(x\)-axis is
The point \((3, -5)\) lies on the line \(mx - y = 11\). The value of \(m\) is
The line \(2x - 3y = 6\) intersects x-axis at
Two coins are tossed simultaneously. The probability of getting at least one head is