List of practice Questions

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
A particle of mass $m$ moves with constant speed along a circular path of radius $r$ under the action of force $F .$ Its speed is
A motor is used to deliver water at a certain rate through a given horizontal pipe. To deliver $n$-times the water through the same pipe in the same time the power of the motor must be increased as follows
The atomic number of an element $ M $ is $26R$ . How many electrons are present in the M-shell of the element in its $M^{3+}$ state?
The raw material used in nylon-$6$ is
Which one of the following reactions is called Rosemond reaction?
Which of the following is the decreasing order of boiling points of $ V $ group hydrides?
A mixture of amylose and amylopectin is called
What is the wave number of $4^{th}$ line in Balmer series of hydrogen spectrum? $(R=1,09,677\,cm^{-1})$
Disperse phase and dispersion medium in butter are respectively
A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness $3 \,cm$ and refractive index $1.5$ is placed over the mark. How should the microscope be moved to get the mark in focus again?
A metal wire of linear mass density of 9.8 g/m is stretched with a tension of 10 kg-wt between two rigid supports 1 m apart. The wire passes at its middle point between the poles of a permanent magnet and it vibrates in resonance when carrying an alternating current of frequency n. The frequency n of the alternating source is
A material B? has twice the specific resistance of ?A?. A circular wire made of B? has twice the diameter of a wire made of ?A?. Then for the two wires to have the same resistance, the ratio $l_{B} / l_{A} $ of their respective lengths must be :