List of practice Questions

The spectral series of the hydrogen atom that lies in the visible region of the electromagnetic spectrum

The work done by a force acting on a body is as shown in the graph. The total work done in covering an initial distance of $20\,m$ is

The resistance of a wire at $300 \, K$ is found to be $0.3 \, \Omega$. If the temperature co-efficient of resistance of wire is $1.5 \times 10^{-3} K^{-1}$, the temperature at which the resistance becomes $0.6\, \Omega$ is

Three concurrent co-planar forces $1\,N, 2\,N$ and $3\,N$ acting along different directions on a body

In fog, photographs of the objects taken with infra-red radiations are more clear than those obtained during visible light because

The diagram of the section of a maize grain is given below. Identify the parts labelled A. B. C and D.

The moment of inertia of a circular ring of radius $'r'$ and mass $'M'$ about diameter is

A body of mass $'m'$ moving along a straight line covers half the distance with a speed of $2\, ms^{-1}$. The remaining half of the distance is covered in two equal time intervals with a speed of $3\, ms^{-1}$ and $5\, ms^{-1}$ respectively. The average speed of the particle for the entire journey is

Two solid pieces, one of steel and the other of aluminium when immersed completely in water have equal weights. When the solid pieces arc weighed in air

Ferromagnetic materials used in a transformer must have

In ruby laser, the stimulated emission is due to transition from

For a first order reaction, the time required for $99.9\%$ of the reaction to take place is nearly

In which of the following molecules / ions $BF _{3},\,NO _{2}^{-}, NH _{2}^{-}$ and $H _{2} O$, the central atom is $sp ^{2}$ hybridized ?

What is the dominant intermolecular force on bond that must be overcome in converting liquid $CH_3 OH$ to a gas?

If $A=\begin{bmatrix} {2}&{1} &{0}\\ {0}&{2}& {1} \\ {1}&{0}&{2}\\ \end{bmatrix}$ then $| adj A|$ =

Triangle $ABC$ has vertices $(0, 0), (11, 60)$ and $(91, 0)$. If the line $ y=kx $ cuts the triangle into $2$ two triangles of equal area, then $k$ is equal to

A metal wire of length $ l $ area of cross-section A and Young's modulus Y behaves as a spring of spring constant k given by

If $\alpha$ and $\beta$ are the roots of $x^2 + x + 1 = 0$ then $\alpha^{16}+\beta^{16}$=

If one side of a triangle is double the other and the angles opposite to these sides differ by $60^\circ$, then the triangle is

In the group $G= \{0, 1,2, 3,4, 5\}$ under addition modulo $6,(2 +_6 3^{-1} +_6 4)^{-1}$=

A bivalent metal has an equivalent mass of $32$. The molecular mass of the metal nitrate is

The smallest positive integral value of $'n'$ such that $\left[\frac {1+\sin \frac {\pi}{8}+\,i\,\cos \frac {\pi}{8}}{1+\sin \frac {\pi}{8}-\,i\,\cos \frac {\pi}{8}} \right]^n$ is purely imaginary is, $n$ =

If $\begin{vmatrix} {1+\sin^2}&{\cos^2 \theta } &{4\sin 2\theta}\\ {\sin^2}&{1+\cos^2}& {4\sin2\theta} \\ {\sin^2\theta}&{\cos^2\theta}&{4\sin2\theta-1}\\ \end{vmatrix} =0 $ and $ 0< \theta

If$\vec{a}.\vec{b}\, = \,- |\vec{a}| \, |\vec{b}|$ then the angle between $\vec{a}$ and $ \vec{b}$ is

If the volume of the parallelopiped with $ \vec{a},\vec{b} $ and $ \vec{c}$ as coterminous edges is $40 \,cubic$ units, then the volume of the parallelopiped having $ \vec{b}+\vec{c} , \vec{c}+ \vec{a} $ and $ \vec{a}+ \vec{b}$ as coterminous edges in cubic units is