List of top Physics Questions

The radius of a spherical drop of water is $1 \,mm$. If surface tension of water be $70\times10^{-3} Nm^{-1},$ the pressure difference inside and outside the drop will be
A black body at $ 1227^{\circ} C $ emits radiations with maximum intensity at a wavelength of $ 5000\,? $ . If the temperature of the body is increased by $ 1000^{\circ} C $ , the maximum intensity will be observed at
A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. Then, the lowest resonant frequency for this string is :
In a common-base mode of a transistor, the collector current is 5.488 mA for an emitter current of 5.60 mA. The value of the base current amplification factor $\left(\beta\right)$ will be :
Which of the following units denotes the dimensions $\frac {ML^{2}} {Q^{2}},$ where $Q$ denotes the electric charge ?
Starting from the origin a body oscillates simple harmonically with a period of 2 s. After what time will its kinetic energy be 75% of the total energy ?
Assuming the sun to be a spherical body of radius R at a temperature of T K, evaluate the total radiant power, incident on earth, at a distance r from the sun : where $r_{0}$ is the radius of the earth and $\sigma$ is Stefan?s constant.
A particle of mass 100 g is thrown vertically upwards with a speed of 5 m/s. The work done by the force of gravity during the time the particle goes up is :
A ball of mass 0.2 kg is thrown vertically upwards by applying a force by hand. If the hand moves 0.2 m while applying die force and the ball goes upto 2 m height further, find the magnitude of the force. Consider g = 10 m/$s^{2}$:
A mass of M kg is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of 45? with the initial vertical direction is :
In Newton ring experiment, monochromatic light is replaced by white light. Then
In a spectrometer experiment, " As wavelength of a spectral line increases, deviation also increases". This is true
In a region a stationary charge does not experience a force. It is certain that in this region
Fine structure of spectral lines is accounted in Sommerfeld atom model by considering
A $ 20 \, \mu F $ capacitor is connected to $ 45 \,V $ battery through a circuit whose resistance is $ 2000\, \Omega $ . What is the final charge on the capacitor?
Oxygen and hydrogen are at the same temperature $ T $ . The ratio of the mean kinetic energy of oxygen molecules to that of the hydrogen molecules will be
If $200\,MeV$ energy is released in the fission of a single nucleus of ${ }_{92} U ^{235}$, how many fissions must occur per second to produce a power of $1 \,kW ?$
Find ratio of acceleration due to gravity $g$ depth d and at height $h$, where $d = 2h$.
In the propagation of light waves, the angle between the direction of vibration and plane of polarization is
A light emitting diode (LED) has a voltage drop of $2\, V$ across it and passes a current of $10\, mA$. When it operates with a $6\, V$ battery through a limiting resistor $R$, the value of $R$ is
The minimum potential difference between the base and emitter required to switch a silicon transistor ON is approximately
At what speed, the velocity head of water is equal to pressure head of $40 \,cm$ of $Hg$?
A solid sphere rolls down two different inclined planes of same height, but of different inclinations. In both cases
A point initially at rest moves along $x$ -axis. Its acceleration varies with time as $a=(6 t+5) \,m / s ^{2} .$ If it starts from origin, the distance covered in $2 s$ is
If $E=$ energy, $G=$ gravitational constant, $I=$ impulse and $M=$ mass, then dimensions of $\frac{G I M^{2}}{E^{2}}$ are same as that of