List of practice Questions

Which one of the following is essential for photolysis of water?
In photoelectric emission process from a metal of work function $1.8\, eV$, the kinetic energy of most energetic electrons is $0.5\, eV$. The corresponding stopping potential is
If $\frac{x^{2}+2x+7}{2x+3} < 6, x\,\in\,R, $ then
A theatre of volume $100 \times 40 \times 10m^3$ can accommodate 1000 visitors. The reverberation time of the theatre when empty is 8.5 s. If the theatre is now filled with 500 visitors, occupying the front-half seats, the reverberation time changes to 6.2 s. The average absorption coeficient of each visitor is nearly
The maximum tension a rope can withstand is $60\, kg-wt.$ The ratio of maximum acceleration with which two boys of masses $20 \,kg$ and $30 \,kg$ can climb up the rope at the same time is
A uniform chain of length $L$ is lying on the horizontal table. If the coefficient of friction between the chain and the table top is $\mu$, what is the maximum length of the chain that can hang over the edge of the table without disturbing the rest of the chain on the table?
A large proportion of oxygen is left unused in the human blood even after its uptakes by the body tissues. This $O _{2}$ :
If for some reason, the vasa efferentia in the human reproductive system get blocked, the gametes will not be transported from
Which one of the following have the highest number of species in nature ?
Consider the following four statements $(A-D)$ related to the common frog Rana tigrina, and select the correct option stating which ones are true $(T)$ and which ones are false $(F)$ . Statements : (A) On dry land it would die due to lack of $O _{2}$ if its mouth is forcibly kept closed for a few days (B) it has four-chambered heart (C) On dry land it turns uricotelic from ureotelic (D) Its life-history is carried out in pond water
The unequivocal proof of DNA as the genetic material came from the studies on a
The de Broglie wavelength of a particle with mass 1 kg and velocity 100 m/s is
A biconvex lens has a radius of curvature of magnitude $20\, cm$. Which one of the following options describe best the image formed of an object of height $2 \,cm$ placed $30\, cm$ from the lens?
: Higher the molal depression constant of the solvent used, higher the freezing point of the solution. : Depression in freezing point does not depend on the nature of the solvent.
The standard reduction potential $E^o$ for half reations are $Zn = Zn^{2+} + 2e^- ;\,\,E^o = +0.76 V$ $Fe = Fe^{2+} + 2e^-;\,\, E^o = + 0.41 V$ The EMF of hte cell reaction $Fe^{2+} + Zn = Zn^{2+} + Fe$ is
$20\, mL$ of $0.2\, M \,NaOH$ is added to $50\, mL$ of $0.2\, M$ acetic acid. The pH of this solution after mixing is $(Ka = 1.8 \times 10^{-5})$
$2\,gm$ of metal carbonate is neutralized completely by $100 \,mL$ of $0.1 \,(N) \,HCl$. The equivalent weight of metal carbonate is
The pH of an aqueous solution of $CH_3COONa$ of concentrated $C(M)$ is given by
The normality of $30$ volume $H_2O_2$ is
A body floats in water with $40\%$ of its volume outside water. When the same body floats in an oil, $60\%$ of its volume remains outside oil. The relative density of oil is
If the focal length of the eye-piece of a telescope is doubled, its magnifying power $(m)$ will be
Some vascular bundles are described as open because these
The sequence $\log \,a$, $\log \frac{a^{2}}{b}, \,\log \frac{a^{3}}{b^{2}}, ...........$ is
The density of a material in $CGS$ system of units is $4\,g\,cm^3$. In a system of units in which unit of length is $10\,cm$ and unit of mass is $100\,g$. the value of density of material will be
As per chemiosmotic coupling hypothesis, in mitochondria, protons accumulate in the