List of practice Questions

A stationary wave is formed having 4 nodes along the $120\,\text{cm$ length of the string. The wavelength of the wave is}

A block of mass $m$, kept on a horizontal surface, is moved through a distance $s$ by applying a horizontal force $F$ to it. What is the work done by the normal reaction?

Two small drops of liquid of same radius coalesce to form a big drop. The ratio of the total surface energies after and before the change is

For a particle performing S.H.M., the displacement–time graph is as shown.

The digital signals are used for transmission in communication system. They are

In biprism experiment, a source of monochromatic light is used for a certain distance between slit and eyepiece. When the distance between two virtual sources is changed from $d_A$ to $d_B$, then the fringe width is changed from $Z_A$ to $Z_B$. The ratio $Z_A$ to $Z_B$ is

A parallel beam of monochromatic light of wavelength $5\times10^{-7\,\text{m}$ is incident normally on a single narrow slit of width $10^{-3}\,\text{mm}$. At what angle of diffraction, the first minima is observed?}

Two identical thin bar magnets are placed mutually at right angles such that the north pole of one touches the south pole of the other. The length of each bar magnet is $\ell$. The magnitude of resultant magnetic moment of the system is
$\left[m = \text{pole strength of the magnet}\right]$

A string of mass $0.1\,\text{kg$ is under a tension $1.6\,\text{N}$. The length of the string is $1\,\text{m}$. A transverse wave starts from one end of the string. The time taken by the wave to reach the other end is}

Which one of the following statements is NOT the property of light?

Relative permeability of an iron is $5500$, then its magnetic susceptibility will be

A capacitor is charged by a battery and energy stored is $U$. Now the battery is removed and the distance between plates is increased to four times. The energy stored becomes

The excess pressure inside a spherical drop of water is three times that of another drop of water. The ratio of their surface area is

Two concentric circular coils having radii $r_1$ and $r_2$ $(r_2 \ll r_1)$ are placed co-axially with centres coinciding. The mutual induction of the arrangement is (Both coils have single turn, $\mu_0$ = permeability of free space)

If the potential difference used to accelerate electrons is doubled, by what factor does the de-Broglie wavelength associated with the electrons change?

A solid sphere of mass $M$ and radius $R$ is rotating about its diameter. A disc of same mass and radius is also rotating about an axis passing through its centre and perpendicular to the plane but angular speed is twice that of the sphere. The ratio of kinetic energy of disc to that of sphere is

The figure shows two diagrams in which diode and resistance are connected. Out of the following statements which one is TRUE?

Two progressive waves $Y_1=\sin 2\pi\left(\dfrac{t}{4}-\dfrac{x}{4}\right)$ and $Y_2=\sin 2\pi\left(\dfrac{t}{4}+\dfrac{x}{4}\right)$ superpose to form a standing wave. $Y_1$ and $Y_2$ are in SI system. Amplitude of the particle at $x=0.5\,\text{m$ is}
$\left[\sin 45^\circ=\cos 45^\circ=\dfrac{1}{\sqrt{2}}\right]$

Earth revolves round the sun in a circular orbit of radius $R$. The angular momentum of the revolving earth is directly proportional to

Let the two forces have equal magnitude $A$. If the magnitude of the resultant is $\dfrac{2A{3}$, then the angle between those two forces is}

A graph of magnetic flux $\phi$ versus current $(I)$ is shown for four inductors A, B, C, D. Smaller value of self inductance is for inductor

The equation of a normal to the curve \[ x = 4\sec\theta,\qquad y = 4\tan^2\theta \] at \( \theta = \frac{\pi}{4} \) is

The equation of the curve which passes through the point \( (1,0) \) and has tangent with slope \[ 1+\frac{y}{x}+\left(\frac{y}{x}\right)^2 \] is

If the function \[ f(x)= \begin{cases} \dfrac{1-\sin2x+\cos2x}{1+\sin2x+\cos2x}, & x\neq \dfrac{\pi}{2}
k, & x=\dfrac{\pi}{2} \end{cases} \] is continuous at \( x=\dfrac{\pi}{2} \), then \( k \) is

Two spheres $S_1$ and $S_2$ have radii $R$ and $3R$, temperature $T$ K and $\dfrac{T{\sqrt{3}}$ K respectively. If they are coated with a material of same emissivity, rate of radiation of $S_1$ is $E$ then rate of radiation of $S_2$ is}