List of top Physics Questions asked in BITSAT

Kepler's third law states that square of period of revolution $(T)$ of a planet around the sun, is proportional to third power of average distance $r$ between sun and planet i.e. $T^{2}=K r^{3}$ here $K$ is constant. If the masses of sun and planet are $M$ and $m$ respectively then as per Newton's law of gravitation force of attraction between them is $F=\frac{G M m}{r^{2}}$ here $G$ is gravitational constant. The relation between $G$ and $K$ is described as

Find the number of photon emitted per second by a $25$ watt source of monochromatic light of wavelength $ 6600\, ??. What is the photoelectric current assuming $3\%$ efficiency for photoelectric effect ?

Two identical charged spheres suspended from a common point by two massless strings of lengths $l$, are initially at a distance $d(d < < l)$ apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity $v$. Then $v$ varies as a function of the distance $x$ between the spheres, as:

Two spheres of different materials one with double the radius and one-fourth wall thickness of the other are filled with ice. If the time taken for complete melting of ice in the larger sphere is $25$ minute and for smaller one is $16$ minute, the ratio of thermal conductivities of the materials of larger spheres to that of smaller sphere is

For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index :

An elastic string of unstretched length $L$ and force constant $k$ is stretched by a small length $x$. It is further stretched by another small length $y$. The work done in the second stretching is

A thin rod of length $4l$, mass $4\, m$ is bent at the points as shown in figure. What is the moment of inertia of the rod about the axis passing point $O$ and perpendicular to the plane of the paper?

An artificial satellite is moving in a circular orbit around the earth with a speed equal to half the magnitude of the escape velocity from the earth. The height $(h)$ of the satellite above the earth?s surface is (Take radius of earth as $R_e$)

A solid sphere of radius $R$ has a charge $Q$ distributed in its volume with a charge density $\rho=k r^{a}$, where $k$ and a are constants and $r$ is the distance from its center. If the electric field at $r =\frac{R}{2}$ is times that at $r = R$, the value of $a$ is

The frequency of a sonometer wire is $100\, Hz$. When the weights producing the tensions are completely immersed in water, the frequency becomes $80\, Hz$ and on immersing the weights in a certain liquid, the frequency becomes $60\, Hz$. The specific gravity of the liquid is

A charged particle moving in a uniform magnetic field and losses $4\%$ of its kinetic energy. The radius of curvature of its path changes by

In figure, two blocks are separated by a uniform strut attached to each block with frictionless pins. Block $A$ weighs $400\, N$, block $B$ weighs $300\, N$, and the strut $A B$ weigh $200\, N$. If $\mu=0.25$ under $B$, determine the minimum coefficient of friction under $A$ to prevent motion.

The approximate depth of an ocean is $2700\, m$. The compressibility of water is $45.4 ? 10^{-11} Pa^{-1 }$ and density of water is $10^3\, kg/m^3$.What fractional compression of water will be obtained at the bottom of the ocean ?

The displacement of a particle is given at time $t$, by $x=A \sin (-2 \omega t)+B \sin ^{2} \omega t$ Then

Calculate the wavelength of light used in an interference experiment from the following data : Fringe width $= 0.03\, cm$. Distance between the slits and eyepiece through which the interference pattern is observed is $1\,m$. Distance between the images of the virtual source when a convex lens of focal length $16\, cm$ is used at a distance of $80\, cm$ from the eyepiece is $0.8\, cm$.

The masses of blocks $A$ and $B$ are $m$ and $M$ respectively. Between $A$ and $B$, there is a constant frictional force $F$ and $B$ can slide on a smooth horizontal surface. $A$ is set in motion with velocity while $B$ is at rest. What is the distance moved by $A$ relative to $B$ before they move with the same velocity?

Two tuning forks with natural frequencies $340\,Hz$ each move relative to a stationary observer. One fork moves away from the observer, while the other moves towards the observer at the same speed. The observer hears beats of frequency $3\, Hz$. Find the speed of the tuning forks.

The efficiency of fuel cell is given by the expression, $\eta$ is

In $CE$ transistor amplifier, the audio signal voltage across the collector resistance of $2\, k \Omega$ is $2\, V$. If the base resistance is $1\, k \Omega$ and the current amplification of the transistor is $100$, the input signal voltage is

In a YDSE, the light of wavelength $I=5000\,�$ is used, which emerges in phase from two slits a distance $d=3 \times 10^{-7} m$ apart. A transparent sheet of thickness $t=1.5 \times 10^{-7} m$ refractive index $\mu=1.17$ is placed over one of the slits. what is the new angular position of the central maxima of the interference pattern, from the center of the screen? Find the value of $y$.

At the corners of an equilateral triangle of side a ( $1$ meter), three point charges are placed (each of $0.1\, C$ ). If this system is supplied energy at the rate of $1\, kw$, then calculate the time required to move one of the mid-point of the line joining the other two.

A train accelerating uniformly from rest attains a maximum speed of $40 \,ms ^{-1}$ in $20\, s$. It travels at the speed for $20\, s$ and is brought to rest with uniform retardation in further $40\, s$. What is the average velocity during the period?

A small block of mass $m$ is kept on a rough inclined surface of inclination $\theta $ fixed in a elevator. The elevator goes up with a uniform velocity $v$ and the block does not slide on the wedge. The work done by the force of friction on the block in time $t$ will be :

A projectile is fired with a velocity $u$ making an angle $\theta $ with the horizontal. What is the magnitude of change in velocity when it is at the highest point -