List of top Physics Questions

A mass of $2.0\, kg$ is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring and the pan is negligible. When pressed slightly and released the mass executes a simple harmonic motion . The spring constant is $200\, N/m$ . What should be the minimum amplitude of the motion so that the mass gets detached from the pan (take $g = 10 \,m /s^2 $).

A body is released from a great height falls freely towards the earth. Another body is released from the same height exactly a second latter. Then the separation between two bodies, $2\,s$ after the release of the second body is, nearly

In an interference experiment, when a glass plate of refractive index 1.5 is introduced in the path of one of the beams; fringes are displaced by $x$. When the glass plate is replaced by another transparent plate of same thickness, shift in the fringe is $ \frac{3}{2} x .$ Refractive index of $2^{nd}$ transparent plate is

The normal atmospheric pressure can support water column of height L which is, (given density of mercury = $13600\, kg\, m^{-3}$)

If the diameter of a capillary tube is doubled, the rate of flow ofliquid increases

A charge $Q$ is to be divided into two parts, $q$ and $(Q- q)$, such that force between them is maximum. Then

To increase the angular width of interference fringes

A bulb is kept at a depth h inside water of refractive index $' n' $. Area of the bright patch on the water surface is

The ratio of forces between two point charges in the two cases when their separation is halved and when it is doubled, is

Two points separated by a distance of 0.1 mm can just be observed using a microscope when light $\lambda = 600\: nm$ is used. If light of wavelength 480 nm is used, this limit of resolution becomes

In Young's double slit experiment, intensity at a bright fringe is $I_0$. One of the slits is closed. Intensity at the same position is

An object radiates at temperature $127^{\circ} C$. Temperature. at which radiates 16 times more is

The speed of electromagnetic radiation in vacuum

$A, B$ and $C$ are three voltmeters of resistances $4000 \, \Omega , 6000 \Omega$ and $12000 \Omega$. When a potential difference? is applied between $X$ and $Y$, voltmeter readings are $V_A, V_B$ and $V_C$. Then

The kinetic energy of the photoelectrons increases by $0.52 \, eV$ when the wavelength of incident light is changed from $500 \, nm$ to another wavelength which is approximately

The capacitance of the Earth considered as a conducting sphere of radius $6408 \, km$ is

A spring balance carries a load. When the load is pulled aside so that the balance makes an angle of $30^{\circ}$ with the vertical, the balance reads $4 \, kg\, wt$. The mass of the load is

An open $ U $ -tube contains mercury. When $ 11.2 \,cm $ of water is poured into one of the arms of the tube, how high does the mercury rise in the other arm from its initial unit ?

We consider a thermodynamic system. If $ \Delta U $ represents the increase in its internal energy and $ W $ the work done by the system, which of the following statements is true ?

A particle moving along $x$ -axis has acceleration $f$, at time $t$, given by $f = f _{0}\left(1-\frac{ t }{ T }\right)$, where $f _{0}$ and $T$ are constants. The particle at $t =0$ has zero velocity. In the time interval between $t =0$ and the instant when $f =0$, the particle's velocity $\left( v _{ x }\right)$ is:

Assuming the sun to have a spherical outer surface of radius r, radiating like a black body at temperature $t^{\circ} C$, the power received by a unit surface, (normal to the incident rays) at distance $R$ from the centre of the Sun is:- Where $\sigma$ is the Stefan's Constant.

$A$ vertical spring with force constant $k$ is fixed on a table. $A$ ball of mass m at a height h above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance $d$ . The net work done in the process is

Dimensions of resistance in an electrical circuit, in terms of dimension of mass $M$, of length $L$, of time $T$ and of current $I$, would be

n-type semiconductor is obtained on doping intrinsic germanium by