List of top Physics Questions

A far sighted person has his near point 50 cm, find the power of lens he should use to see at 25 cm, clearly.
A wave is expressed by the equation $ y= a\,sin [\frac{\pi x}{2a} - \frac{\pi t}{2}]$ where $x$ and $y$ are in $m$ and $t$ in $s$. The distance travelled by the wave in $3 \,s$ is
What will be the effect of using white light in place of sodium light in the Young's double slit experiment?
For which of the following voltages will the wavelengh of emitted $X$-rays will be minimum?
According to Bohr's model, relation between the radius of an orbit and principal quantum number is
A cylindrical tube, open at both ends, has a fundamental frequency $f$ in air. The tube is dipped vertically in water so that half of it is in water. The fundamental frequency of the air column is
The work done in shifting a particle of mass $m$ from the centre of the earth to the surface of the earth is (Where $M$ is the mass of the earth and $R$ is the radius of the earth)
A thermally insulated vessel containing a gas whose molar mass is $M$ and ratio of specific heat $\gamma$ moves with velocity $v$. What is the change in temperature of the gas if the vessel is suddenly stopped?
A car is fitted with a convex side-view mirror of focal length $20 \,cm$. A second car $2.5\, m$ behind the first car is overtaking the first car at a relative speed of $15 \,m / s$. The speed of the image of the second car as seen in the mirror of the first one is
A body of mass $0.5\, kg$ is projected under gravity with a speed of $98\, m / s$ at an angle of $60^{\circ}$ with the horizontal. The change in momentum (in magnitude) of the body is
In a Young's double slit experiment, the two slits act as coherent sources of waves of equal amplitude A and wavelength $\lambda$. In another experiment with the same arrangement the two slits are made to act as incoherent sources of waves of same amplitude and wavelength. If the intensity at the middle point of the screen in the first case is $I_1$ and in the second case is $I_2$, then the ratio $\frac{I_{1}}{I_{2}} $ is :
A beaker contains water up to a height $h_1$ and kerosene of height $h_2$ above water so that the total height of (water + kerosene) is $(h_1 + h_2)$. Refractive index of water is $\mu_{1}$ and that of kerosene is $\mu_{2}$. The apparent shift in the position of the bottom of the beaker when viewed from above is :
A rocket is fired upward from the earth surface such that it creates an acceleration of $19.6\, m / s ^{2}$. If after $5\, s$, its engine is switched off, the maximum height of the rocket from earth's surface would be
A $60\, kg$ weight is dragged on a horizontal surface by a rope through a distance of $2m$. If coefficient of friction is $ \mu =0.5, $ the angle of rope with surface is $60^{\circ}$ and $g=9.8\,m/{s}^{2}, $ then work done is
An ideal coil of $10\, H$ is joined in series with a resistance of $5 \,\Omega$ and battery of $5\, V,\, 2 s$ after joining the current flowing (in ampere) in the circuit will be
Two tangent galvanometer having coils of the same radius are connected in series. A current flowing in them produces deflection of $60^{\circ}$ and $45^{\circ}$ respectively. The ratio of the number of turns in the coils is
As shown in the figure a magnet is moved with a fast speed towards a coil at rest. Due to this induced emf, induced current and induced charge in the coil is $E,\, I$ and $Q$ respectively. If the speed of the magnet is doubled, the incorrect statement is
A 0.2 kg object at rest is subjected to a force $\left(0.3\hat{i}-0.4\hat{ j}\right)$ N. What is the velocity after 6 s?
Two longitudinal waves given by equations : $y_1 (x, t) = 2a$ sin ($\omega t - kx$) and $y_2 (x, t)$ = a sin ($2\omega t - 2kx$) will have equal intensity. Intensity of waves of given frequency in same medium is proportional to square of amplitude only.
The transverse displacement $y(x, t)$ of a wave on a string is given by $y(x, t)=e^{-\left(a x^{2}+b t^{2}+2 \sqrt{a b} x t\right)}$ This represents a :
A body of mass $5\, kg $ is moving with a momentum of $10\,kg\,m/s $ . A force of $ 0.2\,N $ acts on it in the direction of motion of the body for $10\, s$. The increase in its kinetic energy is
A thin circular ring of mass $ M $ and radius $ r $ is rotating about its axis with constant angular velocity $ \omega $ . Two objects each of mass $ m $ , are placed gently at the opposite ends of diameter of the ring. The ring now rotates with an angular velocity
A parallel plate capacitor of value 1.77 $ \mu $ F is to be designed using a dielectric material (dielectric constant = 200), breakdown strength of $ 3\times {{10}^{6}} $ V/m. In order to make such a capacitor which can withstand a potential difference of 20 V across the plates, the separation between the plates d and area A of the plates respectively are
Two lamps of powers $ {{P}_{1}} $ and $ {{P}_{2}} $ are placed on either side of a paper having an oil spot. The lamps are at distances of 1 m and 2 m respectively on either side of the paper and the oil spot is invisible. What is the value of $ {{P}_{1}}/{{P}_{2}} $ ?
At what temperature is rms speed of air molecules double of that at NTP?