List of practice Questions

Anoxygenic photosynthesis is characteristic of

The barrier potential of a $p-n$ junction depends on (1) type of semiconductor material (2) amount of doping (3) temperature Which one of the following is correct?

A gaseous reaction $X_2(g) \to Y + \frac{1}{2} Z(g)$ There is increase in pressure from $100 \,mm$ to $120 \,mm$ in $5$ minutes. The rate of disappearance of $X_2$ is

For the reaction, 3A + 2B $\to$ C + D, the differential rate law can be written as :

$2.76\, g$ of silver carbonate on being strongly heated yields a residue weighing

Which of the following hormones is produced under the condition of stress which stimulates glycogenolysis in the liver of human beings?

The hormone releasing IUD is

Geitonogamy involves

On heating water, bubbles being formed at the bottom of the vessel detatch and rise. Take the bubbles to be spheres of radius $R$ and making a circular contact of radius r with the bottom of the vessel. If $r << R$, and the surface tension of water is T, value of r just before bubbles detatch is (density of water is $\rho_{w}$ )

The ratio of the accelerations for a solid sphere (mass m and radius R) rolling down an incline of angle $ \theta $ without slipping and slipping down the incline without rolling is

The reaction of aqueous $KMnO_4$ with $ H_2O_2 $ in acidic conditions gives

The angular frequency of the damped oscillator is given by, $\omega = \sqrt{\left(\frac{k}{m} - \frac{r^{2}}{4m^{2}}\right)}$ where $k$ is the spring constant, $m$ is the mass of the oscillator and $r$ is the damping constant. If the ratio $\frac{r^{2}}{mk}$ is $8\%$, the change in time period compared to the undamped oscillator is approximately as follows :

The correct order of bond dissociation energy among $N_2, O_2, O_2^-$ is shown in which of the following arrangements ?

The metal that cannot be obtained by electrolysis of an aqueous solution of its salts is

Steel ruptures when a shear of $ 3.5 \times 10^8 \,Nm^{-2}$ is applied. The force needed to punch a $1\, cm$ diameter hole in a steel sheet $0.3\, cm$ thick is nearly :

From the following combinations of physical constants (expressed through their usual symbols) the only combination, that would have the same value in different systems of units, is :

An air bubble of radius $0.1\, cm$ is in a liquid having surface tension $0.06\, N/m$ and density $10^3\, kg/m^3$. The pressure inside the bubble is 1100 $Nm^{-2}$ greater than the atmospheric pressure. At what depth is the bubble below the surface of the liquid ? $(g = 9.8 \,ms^{-2})$

The gap between the plates of a parallel plate capacitor of area A and distance between plates $d$, is filled with a dielectric whose permittivity varies linearly from $\epsilon_{1}$ at one plate to $\epsilon_{2}$ at the other. The capacitance of capacitor is :

A bob of mass m attached to an inextensible string of length l is suspended from a vertical support. The bob rotates in a horizontal circle with an angular speed $\omega \,rad/s$ about the vertical support. About the point of suspension

Reason of lanthanoid contraction is

For the reaction, $ SO_2 ( g) + \frac{1}{2} O_2 \, ( g) \rightleftharpoons SO_3 \, ( g) $ if $ K_P = K_C \, ( RT)^x $ X where, the symbols have usual meaning, then the value of x is (assuming ideality)

Three rods of copper , brass and steel are welded together to form a Y-shaped structure .Area of cross -section of each rod is $4cm^2$.End of copper rod is maintained at $100^{\circ}C$ whereas ends of brass and steel are kept at $0^{\circ C}$ Lengths of the copper, brass and steel rods are 46,13 and 12 cm respectively The rods are thermally insulated from surroundings except at ends.Thermal conductivities of copper , brass and steel are 092 , 0.26 and 0.12 in CGS units , respectively .Rate of heat flow throught cooper rod is

There is a circular tube in a vertical plane. Two liquids which do not mix and of densities $d_1$ and $d_2$ are filled in the tube. Each liquid subtends $90^\circ$ angle at centre. Radius joining their interface makes an angle a with vertical. Ratio $\frac{d_{1}}{d_{2}}$ is :

The octahedral complex of a metal ion $M^{3+} $ with four monodentate ligands $L_1,L_2,L_3 \, and \, L_4 $ absorb wavelengths in the region of red, green, yellow and blue, respectively. The increasing order of ligand strength of the four ligands is

HCl converts pepsinogen into active enzyme pepsin. Pepsin converts protein into proteoses and peptones.