List of top Physics Questions

Absolute zero is the condition at which:
The practical unit of resistance is $ \Omega .1 \, \Omega $ is equal to:
A black body, at a temperature of $227^{\circ} C$, radiates heat at a rate of $20 \,cal\, m ^{-2} s ^{-1} .$ When its temperature is raised to $727^{\circ} C$, the heat radiated by it in $cal \,m ^{-2} s ^{-1}$ will be closest to
A double slit experiment is performed with light of wavelength $500\, nm$. A thin film of thickness $2\, \mu m$ and refractive index $1.5$ is introduced in the path of the upper beam. The location of the central maximum will
A beam of charged particles is employed in the treatment of cancer. Charged particles on passing through a material medium lose their energy by causing ionization of the atoms along their path.
The motion of planets in the solar system is an example of conservation of
In short wave communication, waves of which of the following frequencies will be reflected back by the ionospheric layer having electron density $10^{11}$ per $m ^{3}$ ?
A rectangular loop carrying a current $i_{1}$, is situated near a long straight wire carrying a steady current $i_{2}$. The wire is parallel to one of the sides of the loop and is in the plane of the loop as shown in the figure. Then the current loop will
The difference in the lengths of a mean solar day and a sidereal day is about
The resistivity of a semiconductor increases with temperature. The atoms of a semiconductor vibrate with large amplitude at higher temperatures there by increasing its resistivity.
In an ideal parallel $LC$ circuit, the capacitor is charged by connecting it to a $DC$ source which is then disconnected. The current in the circuit
In an experiment to find the focal length of a concave mirror a graph is drawn between the magnitudcs of $u$ and $v$. The graph looks like
The co-ordinates of a moving particle at any time $'t'$ are given by $x = \alpha t^3$ and $y = \beta t^3$. The speed to the particle at time $'t'$ is given by
Two spherical bodies of mass $'m'$ and $5M$ and radii $R$ and $2R$ respectively are released in free space with initial separation between their centres equal to $12\,R$. If they attract each other due to gravitational force only, then the distance covered by the smaller body just before collision is
Which of the following radiations has the least wavelength?
Dimensions of $\frac{1}{\mu_{0}\,\varepsilon_{0}},$ where symbols have their usual meaning, are
Consider telecommunication through optical fibres. Which of the following statements is not true?
A strip of copper and another germanium are cooled from room temperature to $80\, K$. The resistance of
In an oscillating LC circuit the maximum charge on the capacitor is The charge on the capacitor when the energy is stored equally between the electric and magnetic field is
A tuning fork of known frequency $256\, Hz$ makes $5$ beats per second with the vibrating string of a piano. The beat frequency decreases to $2$ beats per second when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was
When $U^{238}$ nucleus originally at rest, decays by emitting an alpha particle having a speed u, the recoil speed of the residual nucleus is
A circular disc $X$ of radius $R$ is made from an iron pole of thickness $t$, and another disc Y of radius $4R$ is made from an iron plate of thickness $\frac {t}{4}$. then the relation between the moment of inertia $I_X$ and $I_Y$ is
If the work done in blowing a bubble of volume $V$ is $W$, then the work done in blowing a soap bubble of volume $2\, V$ will be :
A magnetic needle suspended in a vertical plane at $30^{\circ}$ from the magnetic meridian makes an angle $45^{\circ}$ with the horizontal. What will be the true angle of dip ?
A force $F$ is given by $F=a t +b t^{2}$, where $t$ is time. What are the dimensions of $a$ and $b$ respectively ?