List of top Questions asked in JCECE

A $ 36\,\Omega $ galvanometer is shunted by resistance of $ 4\,\Omega . $ The percentage of the total current, which passes through the galvanometer is
Let $E_{a}$ be the electric field due to a dipole in its axial plane distant $1$ and let $E _{ q }$ be the field in the equitorial plane distant $1 '$. The relation between $E _{ a }$ and $E _{q}$ is
Most stable carbonium ion is
A solution contains 10 mL 0.1 N NaOH and 10 mL $0.05 NH_2SO_4 $,PH of this solution is
Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio
$[Sc(H_2O)_6 ]^{3+}$ ion is
Which one has the highest boiling point?
Producer gas is the mixture of
In aqueous solutions, the basic strength of amines decreases in the order
Which of the following is the predominant product in the reaction of $ \text{HOBr} $ with propene?
Non-zero dipole moment is shown by
What is the freezing point of a solution containing $ \text{8}\text{.1 g HBr} $ in 100 g water assuming the acid to be 90% ionised? ( $ {{k}_{f}} $ for water $ =1.86\,\text{K}\,\text{mo}{{\text{l}}^{-1}} $ )
Producer gas is the mixture of :
The order of a reaction with rate equal to $kC_A^{3/2} C_B^{-1/2}$ is
The chemical name of vitamin $B_{1}$ is
The centre of mass of three particles of masses 1 kg, 2 kg and 3 kg is at (3, 3, 3) with reference to a fixed coordinate system. Where should a fourth particle of mass 4 kg be placed, so that the centre of mass of the system of all particles shifts to a point (1, 1, 1)?
The $AsF_5$ molecule is trigonal bipyramidal. The hybrid orbitals used by the As atoms for bonding are
The angular width of the central maximum of the diffraction pattern in a single slit of width a experiment, with $ \lambda $ as the wavelength of light, is
At what angle must the two forces (x + y) and (x - y) act so that the resultant may be $\sqrt{x^2 + y^2}$ ?
The most reactive compound towards formation of cyanohydrin on treatment with HCN followed by acidification is
A radioactive material decays by simultaneous emission of two particles with half-lives 1620 yr and 810 yr respectively. The time in year after which one-fourth of the material remains, is
A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is
A ray PQ incident on the refracting face BA is refracted in the prism BA C as shown in the figure and emerges from the other refracting face AC as RS, such that AQ = AR. If the angle of prism $A = 60^\circ$ and the refractive index of the material of prism is $\sqrt 3,$ then the angle of deviation of the ray is
A thin lens made of glass of refractive index $\mu = 1.5$ has a focal length equal to 12 cm in air. lt is now immersed in water $\bigg(\mu = \frac{4}{3}\bigg).$ Its new focal length is
Air is pumped into an automobile tube upto a pressure of 200 kPa in the morning when the air temperature is 22$^{\circ}$C. During the day, temperature rises to 42$^{\circ}$C and the tube expands by 2 %. The pressure of the air in the tube at this temperature, will be approximately