List of top Questions asked in NEET (UG)

Which of the following is not isostructural with \(\text{SiCl}_4\) ?
A 0.5 kg ball moving with a speed of 12 m/s strikes a hard wall at an angle of 30° with the wall. It is reflected with the same speed and at the same angle. If the ball is in contact with the wall for 0.25 s, the average force acting on the wall is :
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 transistor is operated in common emitter configuration at constant collector voltage VC = 1.5 V such that a change in the base current from 100 µA to 150 µA produces a change in the collector current from 5 mA to 10 mA. The current gain (β) is :
In a discharge tube ionization of enclosed gas is produced due to collisions between :
A forward biased diode is :
Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emitted by hydrogen will be :
In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the material is \(\lambda\), then :
Which one of the following statements is correct ?
A transistor-oscillator using a resonant circuit with an inductor L (of negligible resistance) and a capacitor C in series produce oscillations of frequency f. If L is doubled and C is changed to 4C, the frequency will be :
When a charged particle moving with velocity $\vec{v}$ is subjected to a magnetic field of induction $\vec{B}$, the force on it is non-zero. This implies the :-
The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 $\mathring{A}$ is of the order of
The main reason for larger number of oxidation states exhibited by the actinides than the corresponding lanthanides, is :
The correct order in which the O—O bond length increases in the following is:
The correct order of acid strength is
Which one of the following pairs represents stereoisomerism ?
Which one of the following oxides is expected to exhibit paramagnetic behaviour ?
H2S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because:
Aniline in a set of reactions yielded a product D.
 
Aniline


The structure of the product D would be:

At 25°C,the dissociation constant of a base, BOH, is 1.0 x 10-12. The concentration of hydroxyl ions in 0.01 M aqueous solution of the base would be:
Which of the following molecules has trigonal planar geometry?

Which amongst the following is the most stable carbocation?

The mole fraction of the solute in one molal aqueous solution is:
A solution has a 1:4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20°C are 440 mm of Hg for pentane and 120 mm of Hg for hexane. The mole fraction of pentane in the vapour phase would be
The major organic product formed from the following reaction:
(i)CH3NH2 / (ii) LiAlH4 (ii) H2o