List of practice Questions

Two coherent point sources $S_1$ and $S_2$ are separated by a small distance $d$ as shown. The fringes obtained on the screen will be

Bundle sheath cells

If the ratio of diameters, lengths and Young's modulus of steel and copper wires shown in the figure are $p, q$ and $s$ respectively, then the corresponding ratio of increase in their lengths would be :

The wettability of a surface by a liquid depends primarily on

Select the wrong statement :

In china rose the flowers are :

Which one of the following statements is correct ?

The supply voltage in a room is $120\, V$. The resistance of the lead wires is $6 \, \Omega$. A $60\, W$ bulb is already switched on. What is the decrease of voltage across the bulb, when a $240\, W$ heater is switched on in parallel to the bulb?

The order of increasing sizes of atomic radii among the elements $O, S, Se$ and $As$ is :

What is the minimum energy required to launch a satellite of mass $m$ from the surface of a planet of mass $M$ and radius $R$ in a circular orbit at an altitude of $2\,R$ ?

Nitrogen detection in an organic compound is carried out by Lassaigne's test. The blue colour formed corresponds to which of the following formulae ?

Which one of the following is an example of ex-situ conservation ?

Ratio of longest wavelengths corresponding to Lyman and Balmer series in hydrogen spectrum is :

The dimensions of angular momentum, latent heat and capacitance are, respectively.

Which of the following arrangements does not represent the correct order of the property stated against it?

If the time period $t$ of the oscillation of a drop of liquid of density $d$, radius $r$, vibrating under surface tension $s$ is given by the formula $t=\sqrt{r^{2b}s^{c}d^{a/2}}.$ It is observed that the time period is directly proportional to $\sqrt{\frac{d}{s}}.$ The value of $b$ should therefore be :

When the number of nucleons in a nuclues increases the binding energy per nucleons ?

If $\sin x- \sin y = \frac {1}{2}$ and $\cos x- \cos y = 1$, then $ \tan(x + y) $ is equal to

Which one of the following is not a correct statements ?

The density of $3M$ solution of sodium chloride is $1.252\, g\, mL^{-1}$. The molality of the solution will be: (molar mass, $NaCl = 585\, g\, mol^{-1}$)

The value of Planck's constant is $6.63 \times 10^{-34} Js$. The speed of light is $3 \times 10^{17} nm \, s^{-1}$. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of $6 \times 10^{15} \, s^{-1}$ ?

Two pith balls carrying equal charges are suspended from a common point by strings of equal length, the equilibrium separation between them is $r$. Now the strings are rigidly clamped at half the height. The equilibrium separation between the balls now become :

A mass of $50\,g$ of water in a closed vessel, with surroundings at a constant temperature takes $2$ minutes to cool from $30^\circ C$ to $25^\circ C$. A mass of $100\,g$ of another liquid in an identical vessel with identical surroundings takes the same time to cool from $30^\circ C$ to $25^\circ C$. The specific heat of the liquid is: (The water equivalent of the vessel is $30\,g$.)