List of practice Questions

Permanent hardness cannot be removed by

The resistance of $0.01 \,m \,KCl$ solution at $298\, K$ is $1500\, \Omega$. If the conductivity of $0.01\, m \,KCl$ solution at $298\, K$ is $0.146 \,\times \,10^{-3}\, S \,cm ^{-1} .$ The cell constant of the conductivity cell in $cm ^{-1}$ is

Suppose that the electric field amplitude of electromagnetic wave is $E _{0}=120\, NC ^{-1}$ and its frequency if $f =50 \,MHz$. Then which of the following value incorrectly computed ?

What will be the reading in the voltmeter and ammeter of the circuit shown ?

In refraction, light waves are bent on passing from one medium to second medium because, in the second medium.

A toroid with thick windings of $N$ turns has inner and outer radii $R_{1}$ and $R_{2}$ respectively. If it carries certain steady current I, the variation of the magnetic field due to the toroid with radial distance is correctly graphed in

If the refractive index from air to glass is $\frac{3}{2}$ and that from air to water is $\frac{4}{3}$, then the ratio of focal lengths of a glass lens in water and in air is

A vector $\vec{a}$ makes equal acute angles on the coordinate axis. Then the projection of vector $\vec{ b }=5 \hat{ i }+7 \hat{ j }-\hat{ k }$ on $\vec{ a }$ is

Solution of Differential Equation $xdy - ydx = 0$ represents

If $\vec{a} \cdot \vec{b}=0$ and $\vec{a}+\vec{b}$ makes an angle $60^{\circ}$ with $\vec{a} $ then

If the area of the parallelogram with $\vec{a}$ and $\vec{b}$ as two adjacent sides is $15$ s units then the area of the parallelogram having $3 \vec{a}+2 \vec{b}$ and $\vec{a}+3 \vec{b}$ as two adjacent sides in s units is

The equation of the line joining the points $(-3,4,11)$ and $(1,-2,7)$ is

The angle between the lines whose direction cosines are $\left(\frac{\sqrt{3}}{4}, \frac{1}{4}, \frac{\sqrt{3}}{2}\right)$ and $\left(\frac{\sqrt{3}}{4}, \frac{1}{4}, \frac{-\sqrt{3}}{2}\right)$ is

If a plane meets the coordinate axes at $A, B$ and $C$ in such a way that the centroid of triangle $ABC$ is at the point $(1,2,3)$ then the equation of the plane is

The source of electromagnetic wave can be a charge.

To propagate both longitudinal and transverse waves, a material must have

Two bodies of masses $8\, kg$ are placed at the vertices $A$ and $B$ of an equilateral triangle $A B C$. A third body of mas $2\, kg$ is placed at the centroid $G$ of the triangle. If $AG = BG = CG =1 \,m$, where should a fourth body of mass $4 \,kg$ be placed so that the resultant force on the $2\, kg$ body is zero?

DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as :

The electron concentration in an $n$-type semiconductor is the same as hole concentration in a $p$-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.

Complete the flow chart on central dogma.

An infinitely long straight conductor carries a current of $5\, A$ as shown. An electron is moving with a speed of $10^{5} m / s$ parallel to the conductor. The perpendicular distance between the electron and the conductor is $20\, cm$ at an instant. Calculate the magnitude of the force experienced by the electron at that instant.

Choose the correct option for the total pressure (in atm.) in a mixture of $4 \,g\, O _{2}$ and $2 \,g \,H _{2}$ confined in a total volume of one litre at $0^{\circ} C$ is : $\left[\right.$ Given $\left.R = 0.082 \,L \,atm\, mol ^{-1} K ^{-1}, T =273\, K \right]$

DNA fingerprinting involves identifying differences in some specific regions in DNA sequence, called as:

During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out :