List of practice Questions

An $\alpha -$ particle of energy 5 MeV is scattered through $180 ^\circ $ by a fixed uranium nucleus. The distance of the closest approach is of the order of

A spring of spring constant $5 \times 10^3 Nm^{-1}$ is stretched initially by 5 cm from the unstretched position. Then the work required to stretch it further by another 5 cm is

Which one of the following is most reactive towards electrophilic attack ?

Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it?

When $o$- or $ p- $ phenolsulphonic acid is treated with bromine water, the product formed is

Vascular tissues in flowering plants develop from

Vacuole in a plant cell

Keeping in view the 'fluid mosaic model' for the structure of cell membrane, which one of the following statement is correct with respect to the movements of lipids and proteins from one lipid monolayer to the other (described as flipflop movement)?

In Williamson's synthesis, ethoxyethane is prepared by

In which of the following compounds $ -OH $ group is least reactive?

In germinating seeds fatty acids are degraded exclusively in the

If $ N{{a}^{+}} $ ion is larger than $ M{{g}^{2+}} $ ion and $ {{S}^{2-}} $ ion is larger than $Cl^-$ ion, which of the following will be stable soluble in water?

Gel electrophoresis is used for the

Anisole can be prepared by the action of methyl iodide on sodimn phenate. The reaction is called

An organic compound, $ {{C}_{3}}{{H}_{6}}O $ does not give a precipitate with $2, 4$-dinitrophenyl hydrazine reagent and does not react with metallic sodium. It could be

Acetophenone when reacted with a base , $C_2 H_5 ONa,$ yields a stable compound which has the structure . The state of hybridisation of S in $SO_2$ is similar to that of

According to Central Pollution Control Board (CPCB), which particulate size in diameter (in micrometers) of the air pollutants is responsible for greatest harm to human health?

A lake near a village suffered heavy mortality of fishes within a few days. Which of the following statements could be the correct explanation for this? (i) Lots of urea and phosphate fertilisers were used in the crops in the nearby fields. (ii) The croplands of the village were fertilised fields rich in nitrate and phosphate. (iii) The lake water turned green and stinky. (iv) Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis.

Two stretched strings have lengths $l$ and $2l$ while tension are $T$ and $4T$ respectively. If they are made of same material the ratio of their frequency is

Which one of the following statements is true?

Yellowish edges appear in leaves deficient in

What causes chromatic aberration?

The chemical formula of 'tear gas" is

Non-oxide ceramics can be

During the dehydration of alcohols to alkenes by heating with conc. $H_2SO_4$, the initiating step is