List of practice Questions

Magnification of a convex mirror is always positive, but that of a concave mirror may be both positive or negative. It depends on the sign convention chosen.
$KE$ is conserved at every instant of elastic collision. No deformation of matter occurs in elastic collision.
In the transmission of long distance radio signals, short wave band is used. In shorter wavelength, attenuation is very less.
Helium is used in diving apparatus. Solubility of helium is less in blood.
$H_2S$ is less acidic than $H_2$ Te Te has larger radius than S.
Fructose is a reducing sugar. It has a ketonic group.
DNA is present is
Blood in cockroach is colourless haemolymph with no respiratory pigment. Respiration in cockroach occurs through diffusion in haemolymph.
: As a lead storage battery gets discharged, density of electrolyte, present in it, decreases. : Lead and lead dioxide both react with sulphuric acid to form lead sulphate.
Algal blooms are formed in nutrientless water. Algal blooms in water turn it unfit for human consumption, but cause enormous growth of fish.
A mangrove tree growing in marshy place has pneumatophores. Pneumatophores help in better anchorage to marshy soil.
An organic compound $'X'$ on treatment with pyridinium chlorochromate in dichloromethane gives compound $'Y'$ Compound $'Y'$ reacts with $I_{2}$ and alkali to form triiodomethane. The compound $'X'$ is
$CH _{3} COOH \xrightarrow{ LiAlH _{4}}A + CH _{3} COOH \xrightarrow{ H _{3} O ^{+}} B + H _{2} O$ In the above reactions ' $A$ ' and ' $B$ ' respectively are
Which one of the following noble gases is used in miners cap lamps?
The following are some statements related to $VA $ group hydrides, I. Reducing property increases from $NH_{3}$ to $BiH_{3}$ II. Tendency to donate lone pair decreases from $NH_{3}$ to $BiH_{3}$ III. Thermal stability of hydrides decreases from $NH_{3}$ to $BiH_{3}$ IV. Bond angle of hydrides decreases from $NH_{3}$ to $BiH_{3}$ The correct statements are
Which of the following is not tetrahedral?
$138\, g$ of ethyl alcohol is mixed with $72\, g$ of water. The ratio of mole fraction of alcohol to water is
Asexual reproductive structure of Hydra is
Hofmann's bromamide reaction is to convert
The correct order in which the first ionisation potential increases is
When conc. $H _{2} SO _{4}$ is heated with $P _{2} O _{5}$, the acid is converted into
Nitration of nitrobenzene at $125^{\circ} C$ with mixed acids gives
Ammonium ion is
Placoid scales are characteristic feature of the class
The medulla oblongata contains centres which control