List of practice Questions

What are the characteristics of the transition elements and why are they called transition elements? Which of the d-block elements may not be regarded as the transition elements?

What actions of the schoolmates change the author’s understanding of life and people, and comfort him emotionally? How does his loneliness vanish and how does he start participating in life?

DL and BM are the heights on sides AB and AD respectively of parallelogram ABCD (Fig 9.15). If the area of the parallelogram is $1470$ $cm^2$ , AB = $35$ $cm$ and AD = $49$ $cm$, find the length of BM and DL.

What is the force between two small charged spheres having charges of $2 × 10^{−7} C $ and $3 × 10^{−7} C $ placed 30 cm apart in air?

An electric heater is rated 1500 W. How much energy does it use in 10 hours?

A slit of width a is illuminated by red light of wavelength $ 6500\, \overset{\text{o}}{\mathop{\text{A}}}\, $ . If the first minimum falls at $ \theta =30{}^\circ , $ the value of $ a $ is

The time period of rotation of the earth around its axis so that the at the objects at the equator become weightless is nearly $(g=9.8m/s^2)$,Radius of earth =6400 km.

Three bricks each of length $L$ and mass $M$ are arranged as shown from the wall. The distance of the centre of mass of the system from the wall is

The moment of inertia of a thin uniform rod of mass M and length L about an axis passing through its midpoint and perpendicular to its length is $I_0$. Its moment of inertia about an axis passing through one of its ends and perpendicular to its length is

A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time t is proportional to

A projectile has

Why did Santosh’s parents agree to pay for her schooling in Delhi? What mental qualities of Santosh are brought into light by this incident?

A diagonal is a line segment that joins any two vertices of the polygon and is not a side of the polygon. Draw a rough sketch of a pentagon and draw its diagonals.

Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?

An ideal solution of two liquids A and B is placed in a cylinder containing piston. Piston is pulled out isothermally so that the volume of the liquid decreases but that of vapours increases. Negligibly small amount of liquid was left and mole fraction of A in vapour is 0.4. If P⁰A = 0.4 atm and P⁰B at the experimental temperature, which of the following is the total pressure at which the liquid is almost evaporated?

Consider the following statements:1. The nuclear fuels uranium-235 and plutonium-239 are the materials from which nuclear weapons are made.2. Radioactive radon gas is a colourless gas produced from the decay of plutonium.Which of the above given statements is/are correct?

Consider the reaction:VO + Fe2O3 → FeO + V2O5Calculate the weight of FeO produced from 2 g of VO and 5.75 g of Fe2O3.[Take atomic weights of V and Fe to be 51 u and 56 u, respectively.]

In the titration of Fe²⁺ ions versus Cr2O7^2– ions using diphenylamine as the internal indicator, phosphoric acid is added in the solution containing Fe²⁺ ions. The role of phosphoric acid is to

In which of the reactions given below does H2PO4^- behave as an acid?(i)

H_{3} P O_{4} + H_{2} O \to H_{3} O^{+} + H_{2} P O_{4}^{-}

(ii)

H_{2} P O_{4}^{-} + H_{2} O \to H_{3} O^{+} + H P O_{4}^{2 -}

(iii)

H_{2} P O_{4}^{-} + O H^{-} \to H_{3} P O_{4} + O^{2 -}

The variation of pH during the titration of 0.5 N Na2CO3 against 0.5 N HCl is shown in the following graph:

The following table indicates the colour and pH range of different indicators:

Based on the given graph and table, which of the following statements are correct?a. The first point of inflection can be detected by cresolphthalein.b. The complete neutralisation can be detected by bromothymol blue.c. The second point of inflection can be detected by bromocresol red.d. The volume of HCl required for the first point of inflection is half of the volume of HCl required for the second point of inflection.

What will happen to the volume of a bubble of air found under water in a lake, where the temperature is 15^oC and the pressure is 1.5 atm, if the bubble rises to the surface where the temperature is 25^oC and the pressure is 1.0 atm?