List of practice Questions

Vessels and companion cells are found in
Consider a soap film on a rectangular frame of wire of area $4 \times 4\, cm ^{2}$. If the area of the soap film is increased to $4 \times 5 \,cm ^{2}$, the work done in the process will be (The surface tension of the soap film is $3 \times 10^{-2} \,N / m .$ )
A small mass attached to a string rotates on a frictionless table top as shown. If the tension in the string is increased by pulling the string causing the radius of the circular motion to decrease by a factor of $2$ , the kinetic energy of the mass will
The complexes $[Co(NH_3)_6][Cr(CN)_6]$ and $[Cr(NH_3)_6][Co(CN)_6]$ are the examples of which type of isomerism?
A 0.1 molal aqueous solution of a weak acid is 30% ionized. If $K_f$ for water is $ 1.86^{\circ} C/m$, the freezing point of the solution will be -
The process of $RNA$ interference has been used in the development of plants resistant to
A charge $Q$ is enclosed by a Gaussian spherical surface of radius $R$. If the radius is doubled, then the outward electric flux will
Organisms called methanogens are most abundant in a
Two friends are eating together on a dining table. One of them suddenly starts coughing while swallowing some food. This coughing would have been due to improper movement of
The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number $Z$ of hydrogen like ion is
Two identical piano wires, kept under the same tension $T$ have a fundamental frequency of $600 \,Hz$. The fractional increase in the tension of one of the wires which will lead to occurrence of $6 $ beat's when both the wires oscillate together would be
A particle executes a simple harmonic motion of time period $ T $ . Find the time taken by the particle to go directly from its mean position to half the amplitude
If the equilibrium constants of the following equilibria ${SO_{2(g)} +\frac{1}{2}O2 <=> SO3$ $ and\, 2SO_{3(g)} <=> 2SO_{2(g)} +O_{2(g)}}$ are given by $K_1$ and $K_2$ respectively, which of the following relations is correct
Two soap bubbles of radii $x$ and $y$ coalesce to constitute a bubble of radius $z$. Then $z$ is equal to
Arteries are best defined as vessels which
About which day in a normal human menstrual cycle does rapid secretion of $LH$ (popularly called $LH$ surge) normally occurs?
The Lassaigne's extract is boiled with conc. $HNO_3$ while testing for halogens. By doing so it
$200 \,mL$ of an aqueous solution of a protein contains its $1.26\, g$. The Osmotic pressure of this solution at $300\, K$ is found to be $2.57 \times 10^{-3}$ bar. The molar mass of protein will be ($R = 0.083 \, L\, bar\, mol^{-1} \, K^{-1}$):
Both hydrarch and xerarch successions lead to
A converging beam of rays is incident on a diverging lens. Having passed through the lens the rays intersect at a point $15\,cm$ from the lens on the opposite side. If the lens is removed the point where the rays meet will move $5\,cm$ closer to the lens. The focal length of the lens is
Biodiversity of geographical region represents
The cells lining the blood vessels belong to the category of
The cork cambium, cork and secondary cortex are collectively called :
The power obtained in a reactor using $U^{235}$ disintegration is $1000\, {kW}$. The mass decay of $U^{235}$ per hour is
Pure $Si$ at $500\, K$ has equal number of electron $(n_e)$ and hole $(n_h)$ concentrations of $1.5 \times 10^{16}\, m^{-3}$ Doping by indium increases $n_h$ to 4.5 $\times 10^{22}\, m^{-3}$ The doped semiconductor is of