List of practice Questions

A train moving at a speed of $220\,ms^{-1}$ towards a stationary object, emits a sound of frequency $1000\, Hz$. Some of the sound reaching the object gets reflected back to the train as echo. The frequency of the echo as detected by the driver of the train is (Speed of sound in air is $330\,ms^{-1}$)

Which one of the following is a mineral of iron?

A milli voltmeter of $25$ milli volt range is to be converted into an ammeter of $25$ ampere range. The value (in ohm) of necessary shunt will be

Consider the reaction: ${ RCHO + NH2NH2 -> RCH = N - NH2 }$ What sort of reaction is it ?

In the following sequence of reactions, \(CH _{3}- Br \stackrel{ KCN }{\longrightarrow} A \stackrel{ H _{3} O ^{+}}{\longrightarrow} B \stackrel{ LiAlH _{4}}{\longrightarrow} C\), the end product C is

A spherical planet has a mass $M_p$ and diameter $D_p$. A particle of mass $m$ falling freely near the surface of this planet will experience an acceleration due to gravity, equal to

During gamete formation, the enzyme recombinase participates during

To get the maximum flight, a ball must be thrown as

An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be ($m$ is the mass of the electron, $R$, Rydberg constant and $h$ Planck's constant)

Cirrhosis of liver is caused by the chronic intake of

$F _{2}$ generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as $1: 2: 1.$ It represents a case of

The compressibility factor for a real gas at high pressure is :

Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state.
The ratio of the wavelengths \(\lambda_1 : \lambda_2\) emitted in the two cases is:

A magnetic needle suspended parallel to a magnetic field requires $\sqrt 3 \,J$ of work to turn it through $60^\circ.$ The torque needed to maintain the needle in this position will be

For an ideal system at thermal equilibrium, the velocity distribution of the constituent particles will be governed by

An electron and a proton, both having the same kinetic energy, enter a region of uniform magnetic field, in a plane perpendicular to the field. If their masses are denoted by $m_{e}$ and $m_{p}$ respectively, then the ratio of the radii (electron to proton) of their circular orbits is

The probability that atleast one of the events $A$ and $B$ occurs is $ 0.5 $ . If $A$ and $B$ occur simultaneously with probability $ 0.2, $ then $ P({{A}^{c}})+P({{B}^{c}}) $ is equal to

Let $ f(x)=\frac{k}{1+{{x}^{2}}},\,-\infty < x < \infty $ be the probability density of a random variable. Then, $k$ equals to

The sum of $n$ terms of the series $ \frac{3}{{{1}^{2}}{{.2}^{2}}}+\frac{5}{{{2}^{2}}{{.3}^{2}}}+\frac{7}{{{3}^{2}}{{.4}^{2}}}+..... $ is equal to

What is the resonance frequency of a driven $LCR$ oscillator?

A cheetah, weighing $150 \,kg$, chases a deer, weighing $30 \, kg$, in a straight path. The speed of the cheetah is $20 \,m / s$ and that of the deer is $25 m / s$. The approximate speed of the centre of mass of the pair is

If $(-3, 2)$ lies on the circle $x^2 + y^2 + 2gx + 2fy + c = 0$, which is concentric with the circle $x^2 + y^2 + 6x + 8y - 5 = 0,$ then c is equal to

A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It.

Consider the following reaction ${ ->[H_2][pd-BaSO_4] 'A'}$ The product 'A' is -

The line $x=2 y$ intersects the ellipse $\frac{x^{2}}{4}+y^{2}=1$ at the points $P$ and $Q$. The equation of the circle with $P Q$ as diameter is