List of practice Questions

A hollow double concave lens is made of very thin transparent material. It can be filled with air or either of two liquids \(L_1\space and\space L_2\) having refracting indices \(n_1\space and\space n_2\) respectively \((n_2 > n_1 > 1)\)The lens will diverge a parallel beam of light if it is filled with

If $\alpha$ and $\beta$ are $(\alpha < \beta)$ the roots of the equation $x^2+bx+c=0,$ where $c < 0 < b$,the

If $ x^2 + y^2 = 1$, then

A straight line through the origin O meets the parallel lines $4x + 2y = 9 $ and $2x + y + 6 = 0$ at points P and Q respectively. Then, the point O divides the segment PQ in the ratio

Let f : R $\to$ R be any function. Define g : R $\to$ R by g(x) = |f(x)| for all x. Then g is

For the equation $3x^2+px+3=0,p>0,$ if one of the root is square of the other, then p is equal to

An electron having charge $ 1.6\times {{10}^{-19}} $ and mass $ 9\times {{10}^{-31}}kg $ is moving with $ 4\times {{10}^{6}}m{{s}^{-1}} $ speed in a magnetic field $ 2\times {{10}^{-1}} $ tesla in a circular orbit. The force acting on electron and the radius of the circular orbit will be:

Which of the following is not oxidised by $ KMnO_{4}^{-} $ ?

Biological control of pests is

A satellite is in an orbit around the earth. If its kinetic energy is doubled, then

Choose the correct combination

In the Nuclear reaction given below : $_7N^{14}+2He^4\rightarrow\,X+_1H^1$, the nucleus X is

If $\overrightarrow{a}, \overrightarrow{b}$ and $\overrightarrow{c}$ are unit coplanar vectors, then the scalar triple product $[2\overrightarrow{a}-\overrightarrow{b}2\overrightarrow{b}-\overrightarrow{c}2\overrightarrow{c}-\overrightarrow{a}]$ is

A $60\, W$ incandescent lamp operates at $120\, V$. The number of electrons passing through the filament per second will be

The unit of luminous efficiency of electric bulb is:

$0.1\, M$ solution of glucose has same increment in the freezing point than $0.1\, M$ solution of urea. $K_f$ for both has same value.

On dissolving $1$ mole each of the following acids in $1$ litre water, the acid which do not give a solution of $1 \,N $ strength is:

Partial pressure of a solution component is directly proportional to its mole fraction. This statement is known as

The solubility of a gas is directly proportional to the pressure of the gas. This statement is based on:

Which solutions are mixed to form a buffer solution ?

A simple pendulum has a bob suspended by an inextensible thread of length $1$ metre from a point $A$ of suspension. At the extreme position of oscillation, the thread is suddenly caught by a peg at a point $B$ distant (1/4) m from $A$ and the bob begins to oscillate in the new condition. The change in frequency of oscillation of the pendulum is approximately given by $\left(g=10 m / s ^{2}\right)$.

The period of oscillation of simple pendulum of length $l$ suspended from the roof of the vehicle which moves without friction, down an inclined plane of inclination $\alpha$, is given by

The radium and uranium atoms in a sample of uranium mineral are in the ratio of $1: 2.8 \times 10^{6}$ If half-life period of radium is $1620$ year, the half-life period of uranium will be:

$12\, g$ of an alkaline earth metal gives $14.8\, gm$ of its nitride. Atomic weight of the metal is

Temin was awarded Nobel prize in the year :