List of practice Questions

The equation $x^2 - 2 \sqrt{3} xy + 3y^2 - 3x + 3 \sqrt{3} y - 4 = 0 $ represents

If $\log a, \log b$, and $\log c$ are in A.P. and also $\log a-\log 2 b, \log 2 b-\log 3 c, \log 3 c-\log a$ are in A.P., then

If $\sin^{-1} \left(\frac{2a}{1+a^{2}}\right) -\cos^{-1} \left(\frac{1-b^{2}}{1+b^{2}}\right) = \tan^{-1} \left(\frac{2x}{1-x^{2}}\right) , $ then what is the value of x?

If $\sum\limits^{n}_{r=0} \frac{r+2}{r+1} \,^{n}C_{r} = \frac{2^{8}-1}{6} $, then $n =$

The curve $y = xe^x$ has minimum value equal to

The number of values of $r$ satisfying the equation $^{39}C_{3r-1} - ^{39}C_{r^{2}} = ^{39}C_{r^{2}-1} - ^{39}C_{3r} $ is

Which of the following Options best captures the relationship similar to INSPECT : VIVISECT?

“Assumptions are analogous to the basic ingredients in a gourmet recipe. Only the final product of the recipe dictates whether the ingredients suffice………”
Which of the following is ANALOGOUS to the statement above?

$CH _{3} C \equiv CCH _{3} \xrightarrow{H 2 / P t} A \xrightarrow{D_{2} / P t} B$ The compounds $A$ and $B$, respectively are

Give the possible structure of $X$ in the following reaction : $C_6 H_6 + D_2 SO_4 \xrightarrow{D_2O} X$

The normality of $26\%$ (wt/vol) solution of ammonia (density $= 0.855$ ) is approximately :

At what temperature, the rate of effusion of $N_2$ would be $1.625$ times than that of $SO_2$ at $50^{\circ} C$ ?

$1.25\, g$ of a sample of $Na _{2} CO _{3}$ and $Na _{2} SO _{4}$ is dissolved in $250\, ml$ solution. $25 ml$ of this solution neutralises $20\, ml$ of $0.1\, N\, H _{2} SO _{4}$. The $\%$ of $Na _{2} CO _{3}$ in this sample is

A resistor of resistance $R$, capacitor of capacitance $C$ and inductor of inductance $L$ are connected in parallel to $A C$ power source of voltage $\epsilon_{0} \sin \omega_{t}$. The maximum current through the resistance is half of the maximum current through the power source. Then value of $R$ is

Two identical charged spheres suspended from a common point by two massless strings of lengths $l$, are initially at a distance $d(d < < l)$ apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity $v$. Then $v$ varies as a function of the distance $x$ between the spheres, as:

A source of sound $S$ emitting waves of frequency $100\, Hz$ and an observor $O$ are located at some distance from each other. The source is moving with a speed of $19.4\, m s^{-1}$ at an angle of $60^{\circ}$ with the source observer line as shown in the figure. The observor is at rest. The apparent frequency observed by the observer is (velocity of sound in air $330\, ms ^{-1}$ )

For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index :

A deuteron of kinetic energy $50 \,keV$ is describing a circular orbit of radius $0.5$ metre in a plane perpendicular to the magnetic field $B$. The kinetic energy of the proton that describes a circular orbit of radius $0.5$ metre in the same plane with the same $B$ is

Find the number of photon emitted per second by a $25$ watt source of monochromatic light of wavelength $ 6600\, ??. What is the photoelectric current assuming $3\%$ efficiency for photoelectric effect ?

Kepler's third law states that square of period of revolution $(T)$ of a planet around the sun, is proportional to third power of average distance $r$ between sun and planet i.e. $T^{2}=K r^{3}$ here $K$ is constant. If the masses of sun and planet are $M$ and $m$ respectively then as per Newton's law of gravitation force of attraction between them is $F=\frac{G M m}{r^{2}}$ here $G$ is gravitational constant. The relation between $G$ and $K$ is described as

The approximate depth of an ocean is $2700\, m$. The compressibility of water is $45.4 \times 10^{-11} Pa ^{-1}$ and density of water is $10^{3} kg / m 3 .$ What fractional compression of water will be obtained at the bottom of the ocean?

Two spheres of different materials one with double the radius and one-fourth wall thickness of the other are filled with ice. If the time taken for complete melting of ice in the larger sphere is $25$ minute and for smaller one is $16$ minute, the ratio of thermal conductivities of the materials of larger spheres to that of smaller sphere is