List of top Physics Questions

A thermodynamic state of a given sample of an ideal gas is completely described, if its
A steady current $I$ flows along an infinitely long hollow cylindrical conductor of radius $R$. This cylinder is placed coaxially inside an infinite solenoid of radius $2R$. The solenoid has $n$ turns per unit length and carries a steady current $I$. Consider a point $P$ at a distance $r$ from the common axis. The correct statement(s) is (are)
A particle of mass $m$ is projected from the ground with an initial speed $u _{0}$ at an angle $\alpha$ with the horizontal. At the highest point of its trajectory, it makes a completely inelastic collision with another identical particle, which was thrown vertically upward from the ground with the same initial speed $u_{0}$. The angle that the composite system makes with the horizontal immediately after the collision is
A particle of mass $M$ and positive charge $Q$, moving with a constant velocity $u _{1}=4 \hat{i}ms ^{-1}$, enters a region of uniform static magnetic field normal to the $x$-y plane. The region of the magnetic field extends from $x =$ 0 to $x = L$ for all values of $y$. After passing through this region, the particle emerges on the other side after 10 milliseconds with a velocity $\vec{ u }_{2}=2(\sqrt{3} i +\hat{ j }) m / s ^{-1}$. The correct statement(s) is (are)
A microscope is focused on a coin lying at the bottom of a beaker. The microscope is now raised up by $1 cm$. To what depth should the water be poured into the beaker so that coin is again in focus? (Refractive index of water is $\frac{4}{3}$ )
A magnifying glass of focal length $ 5\,cm $ is used to view an object by a person whose smallest distance of distinct vision is $ 25\,cm $ . If he holds the glass close to eye, the magnification is
A glass plate of refractive index $1.5$ is coated with a thin layer of thickness t and refractive index $1.8$. Light of wavelength $648 \,nm$ travelling in air is incident normally on the layer. It is partly reflected at upper and lower surfaces of the layer and the two reflected rays interfere. The least value of $t$ for which the rays interfere constructively is
A cyclotron is operated at an oscillator frequency of $ 12\, MHz $ and has a dee radius $ R = 50\,cm $ . What is the magnitude of the magnetic field needed for a proton to be accelerated in the cyclotron ?
The image of an object, formed by a plano-convex lens at a distance of $8\,m$ behind the lens, is real and is one-third the size of the object. The wavelength of light inside the lens is $\frac{2}{3}$ times the wavelength in free space. The radius of the curved surface of the lens is
In the Young's double slit experiment using a monochromatic light of wavelength $\lambda$ the path difference (in terms of an integer $n$) corresponding to any point having half the peak intensity is
Two non-reactive monoatomic ideal gases have their atomic masses in the ratio $2 : 3$. The ratio of their partial pressures, when enclosed in a vessel kept at a constant temperature, is $4 : 3$. The ratio of their densities is
A ray of light travelling in the direction $\frac{1}{2}(\hat{i}+\sqrt{3})$ is incident on a plane mirror. After reflection, it travels along the direction $\frac{1}{2}(\hat{i}-\sqrt{3} j)$. The angle of incidence is
Using the expression 2d sin $\theta =\lambda,$ one calculates the values of d by measuring the corresponding angles $\theta$ in the range 0 to 90$^{\circ}$. The wavelength X is exactly known and the error in $\theta$ is constant for all values of $\theta$. As $\theta$ increases from 0$^{\circ}$
Two rectangular blocks, having identical dimensions, can be arranged either in configuration I or in configuration II as shown in the figure. One of the blocks has thermal conductivity $\kappa$ and the other $2 \,\kappa .$ The temperature difference between the ends along the $x$-axis is the same in both the configurations. It takes $9\, s$ to transport a certain amount of heat from the hot end to the cold end in the configuration I. The time to transport the same amount of heat in the configuration II is
A $50\,Hz\,AC$ signal is applied in a circuit of inductance of $ (1/\pi )H $ and resistance $ 2100\,\Omega $ The impedance offered by the circuit is
A $40\, kg$ slab rests on a frictionless floor. A $10\, kg$ block rests on top of the slab (as shown in the figure). The coefficient of static friction $\mu_{s}$ between the block and the slab is $0.60$, whereas their kinetic friction coefficient $\mu_{k}$ is $0.40$. The $10 \,kg$ block is pulled by a horizontal force $(100.0\, N) \hat{i}$. The resulting accelerations of the block and slab will be $\left(\right.$ Take $\left.g=10 \,m / s ^{2}\right)$
The scalar product of two vectors $ \vec{A} =2\hat{i}+2\hat{j}-\hat{k} $ and $\vec{B} = -\hat{j}+\hat{k}, $ is given by
A projectile is thrown with initial velocity $v_{0}$ and angle $30^{\circ}$ with the horizontal. If it remains in the air for $1\, s$, what was its initial velocity?
Uniform circular motion is an example of
The velocity vector of the motion described by the position vector of a particle, $\vec{r}=\left(2 t \hat{i}+t^{2} \hat{j}\right)$ is given by
An organ pipe $A$, with both ends open, has fundamental frequency $300\, Hz$. The third harmonic of another organ pipe $B$, with one end open, has the same frequency as the second harmonic of pipe $A$. The lengths of pipe $A$ and $B$ are (speed of sound in air = $343\, m/s)$
Two waves of wavelengths 50 cm and 51 cm produced 12 beats per sec. The velocity of sound is
The input resistance of a silicon transistor is $665 \,\Omega$. Its base current is changed by $15 \, \mu \,A$ which results in the change in collector current by $2 \,mA$. This transistor is used as a common emitter amplifier with a load resistance of $5\, k\,\Omega$. What is the voltage gain of the amplifier?
If the surface tension of water is ${0.06\, N\, m^{-1}}$, then the capillary rise in a tube of a diameter 1 mm is (Take $\theta$ = 0?)
Hydrogen atom is excited from ground state to another state with principal quantum number equal to $4$. Then the number of spectral lines in the emission spectra will be