List of top Physics Questions

Consider two containers A and B containing monoatomic gases at the same Pressure (P), Volume (V) and Temperature (T). The gas in A is compressed isothermally to \(\frac{1}{8}\) of its original volume while the gas in B is com pressed adiabatically to \(\frac{1}{8}\) of its original volume. The ratio of final pressure of gas in B to that of gas in A is

In normal adjustment, for a refracting telescope, the distance between objective and eye piece is $30\,cm$ The focal length of the objective, when the angular magnification of the telescope is 2, will be:

The disintegration rate of a certain radioactive sample at any instant is $4250$ disintegrations per minute $10$ minutes later, the rate becomes $2250 $ disintegrations per minute The approximate decay constant is : (Take $\log _{10} 188=0274$ )

A radio can tune to any station in $6\, MHz$ to $10\, MHz$ band The value of corresponding wavelength bandwidth will be :

The equation $\lambda=\frac{1227}{ x } nm$ can be used to find the de-Brogli wavelength of an electron In this equation $x$ stands for : Where, $m =$ mass of electron $P =$ momentum of electron $K =$ Kinetic energy of electron $V=$ Accelerating potential in volts for electron

A parallel beam of light of wavelength $900 \,nm$ and intensity $100 \,Wm ^{-2}$ is incident on a surface perpendicular to the beam Tire number of photons crossing $1 \,cm ^2$ area perpendicular to the beam in one second is :

The percentage decrease in the weight of a rocket, when taken to a height of $32 \,km$ above the surface of earth will, be : (Radius of earth $=6400 \,km$ )

Three masses \(M =100 \,kg , m _1=10\, kg\) and \(m _2=20 \,kg\) are arranged in a system as shown in figure All the surfaces are frictionless and strings are inextensible and weightless The pulleys are also weightless and frictionless A force \(F\) is applied on the system so that the mass \(m _2\) moves upward with an acceleration of \(2\, ms ^{-2}\) The value of \(F\) is : (Take \(\text g=10\;ms^-2\))

When a particle executes simple Harmonicmotion, the nature of graph of velocity asfunction of displacement will be :

\(7\) mole of certain monoatomic ideal gas undergoes a temperature increase of \(40\, K\) at constant pressure The increase in the internal energy of the gas in this process is (Given \(R =83\, JK ^{-1}\, mol ^{-1}\))

\(B_X\) and \(B_Y\) are the magnetic field at the centre of two coils of two coils \(X\) and \(Y\) respectively, each carrying equal current If coil \(X\) has \(200\) turns and \(20\, cm\) radius and coil \(Y\) has \(400\) turns and \(20 \,cm\) radius, the ratio of \(B_X\) and \(B_Y\) is

As shown in the figure, after passing through the medium 1. The speed of light v₂ in medium 2 will be: (Given \(c = 3 \times 10^8 ms^{-1}\))

The magnetic field of a plane electromagnetic wave is given by $\vec{ B }=2 \times 10^{-8} \sin \left(05 \times 10^3 x +15 \times 10^{11} t \right) \hat{ j } T$ The amplitude of the electric field would be

As shown in the figure, a metallic rod of linear density \(0.45\ kg m^{-1}\) is lying horizontally on a smooth incline plane which makes an angle of 45° with the horizontal. The minimum current flowing in the rod required to keep it stationary, when \(0.15 T\) magnetic field is acting on it in the vertical upward direction, will be: {Use \(g = 10 m/s^2\)}

The total charge on the system of capacitance $C _1=1\, \mu F , C _2=2 \,\mu F , C _3=4 \,\mu F $ and $C _4=3\, \mu F$ connected in parallel is (Assume a battery of $20 \,V$ is connected to the combination)

In the case of amplitude modulation to avoid distortion the modulation index $(\mu)$ should be:

In young's double slit experiment, the fringe width is $12\, mm$ If the entire arrangement is placed in water of refractive index $\frac{4}{3}$, then the fringe width becomes (in $mm$ )

The half life period of a radioactive substance is 60 days The time taken for $\frac{7}{8}$ th of its original mass to disintegrate will be :

The current sensitivity of a galvanometer can be increased by: 
(A) decreasing the number of turns 
(B) increasing the magnetic field 
(C) decreasing the area of the coil 
(D) decreasing the torsional constant of the spring Choose the most appropriate answer from the options given below:

A charge particle is moving in a uniform magnetic field $(2 \hat{ i }+3 \hat{ j }) T$ If it has an acceleration of $(\alpha \hat{i}-4 \hat{j}) m / s ^2$, then the value of $\alpha$ will be

A wire of resistance $R_1$ is drawn out so that its length is increased by twice of its original length The ratio of new resistance to original resistance is:

In a series LR circuit $X_L=R$ and power factor of the circuit is $P _1$ When capacitor with capacitance $C$ such that $X _{ L }= X _{ C }$ is put in series, the power factor becomes $P _2$ The ratio $\frac{ P _1}{ P _2}$ is

A water drop of radius $1 \,cm$ is broken into $729$ equal droplets If surface tension of water is $75 \,dync / cm$, then the gain in surface energy upto first decimal place will be : [Given $\pi=314]$

A person can throw a ball upto a maximum range of 100 m. How high above the ground he can throw the same ball?