List of practice Questions

Zener diode is used for
Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species?
$4.5\, g$ of aluminium (at. mass $27$ amu) is deposited at cathode from a molten electrolyte containing $Al^{3+}$ ions by a certain quantity of electric charge.The volume of hydrogen produced at STP from $H^+$ ions in a solution by the same quantity of electric charge will be
A solution of urea (mol mass $56\, g\, mol^{-1})$ boils at $100.18 ^\circ\,C$ at the atmospheric pressure. If $K_f$ and $K_b$ for water are $1.86$ and $0.512\, K\, kg$ $mol^{-1}$ the above solution will freeze at
Which functional group participates in disulphide bond formation in proteins?
The cell membranes are mainly composed of
Which one of the following is expected to exhibit optical isomerism? (en = ethylenediamine)
Secretin and cholecystokinin are digestive hormones. They are secreted in
A ball is thrown vertically upward. It has a speed of \(10\ m/s\) when it has reached one half of its maximum height. How high does the ball rise?
(Take \(g = 10\, m/s^2\))
If $ {\lambda }_v , {\lambda }_x,{\lambda }_m $ represent the wavelengths of visible light, X-rays and microwaves respectively, then
Two batteries, one of emf 18 volts and internal resistance $2\, \Omega$ and the other of emf 12 volts and internal resistance $1\, \Omega$ are connected as shown. The voltmeter V will record a reading of
When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between any two of diametrically opposite points will be
A force $F$ acting on an object varies with distance $x$ as shown in the figure. The force is in $N$ and $x$ in $m$. The work done by the force in moving the obiect from $x=0$ to $x = 6 \,m$ is
The displacement x of a particle varies with time t as $x = ae^{-\alpha t}+be^{\beta t}$ where a, b, $\alpha$ and $\beta$ are positive constants. The velocity of the particle will
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:
Which of the following unicellular organisms has a macronucleus for trophic function and one or more micronuclei for reproduction?
As a result of change in the magnetic flux linked to the closed loop as shown in the figure, an e.m.f. V volt is induced in the loop. The work done (joule) in taking a charge Q coulomb once along the loop is
A ball is thrown vertically upward. It has a speed of 10m/s when it has reached one half of its maximum height. How high does the ball rise?(Taking g=10 m/s2)
Photosynthesis in C4 plants is relatively less limited by atmospheric CO2 levels because :
Photosynthetic Active Radiation (PAR) has the following range of wavelengths
In contrast to annelids the platyhelminths show
Which of the following is relatively most accurate method for dating of fossils ?
A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distances of 2 m and 3 m respectively from the source. The ratio of the intensities of the waves at P and Q is
At $ 25^\circ $, the dissociation constant of a base, BOH is $ 1.0 \times 10^{-12} $. The concentration of hydroxyl ions in 0.01 M aqueous solution of the base would be
There exists a close association between the alga and the fungus within a lichen. The fungus