List of top Physics Questions asked in VITEEE, NEET (UG)

Pure $Si$ at $500\, K$ has equal number of electron $(n_e)$ and hole $(n_h)$ concentrations of $1.5 \times 10^{16}\, m^{-3}$ Doping by indium increases $n_h$ to 4.5 $\times 10^{22}\, m^{-3}$ The doped semiconductor is of

The instantaneous angular position of a point on a rotating wheel is given by the equation $\theta(t)=2t^3-6t^2$ The torque on the wheel becomes zero at

The power obtained in a reactor using $U^{235}$ disintegration is $1000\, {kW}$. The mass decay of $U^{235}$ per hour is

The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number $Z$ of hydrogen like ion is

Two radioactive nuclei $P$ and $Q$, in a given sample decay into a stable nucleus $R$. At time $t = 0$, number of $P$ species are $4\, N_0$ and that of $Q$ are $N_0$. Half-life of $P$ (for conversion to $R$) is $1$ minute where as that of $Q$ is $2$ minutes. Initially there are no nuclei of $R$ present in the sample. When number of nuclei of $P$ and $Q$ are equal, the number of nuclei of $R$ present in the sample would be

A person of mass $60\,kg$ is inside a lift of mass $940\,kg$ and presses the button on control panel. The lift starts moving upwards with an acceleration $1.0 \,m/s^2$. If $g = 10\, ms^{-2}$, the tension in the supporting cable is

Which of the following is not due to total internal reflection?

A charge $Q$ is enclosed by a Gaussian spherical surface of radius $R$. If the radius is doubled, then the outward electric flux will

A Zener diode, having breakdown voltage equal to $15\,V$, is used in a voltage regulator circuit shown in figure. The current through the diode is

Electrons used in an electron microscope are accelerated by a voltage of $25\, kV$. If the voltage is increased to $100\, kV$ then the de-Broglie wavelength associated with the electrons would

In photoelectric emission process from a metal of work function $1.8\, eV$, the kinetic energy of most energetic electrons is $0.5\, eV$. The corresponding stopping potential is

The half life of a radioactive isotope $X$ is $50$ years. It decays to another element $Y$ which is stable. The two elements $X$ and $Y$ were found to be in the ratio of $1 : 15$ in a sample of a given rock. The age of the rock was estimated to be

Polarising angle for water is \( 53^\circ 4' \). If light is incident at this angle on the surface of water and reflected, the angle of refraction is:

In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is \( \lambda \) is:

A nucleus \( _{Z}^A X \) emits an \( \alpha \)-particle. The resultant nucleus emits a \( \beta^- \)-particle. The respective atomic and mass numbers of final nucleus will be:

A coil of resistance 100 \( \Omega \) and inductance 5 H is connected to a 100 V battery. Then the energy stored in the coil is:

An ammeter reads up to 1 A. Its internal resistance is 0.81 \( \Omega \). To increase the range to 10 A, the value of the required shunt is:

A 2 V battery, a 15 \( \Omega \) resistor, and a potentiometer of 100 cm length are connected in series. If the resistance of potentiometer wire is 5 \( \Omega \), then the potential gradient of the potentiometer wire is:

The output voltage of a transformer connected to a 220 V line is 1100 V at 2 A current. Its efficiency is 100%. The current coming from the line is:

In an electromagnetic wave, the average energy density associated with magnetic field is:

Five resistances are connected as shown in the figure. The effective resistance between points A and B is:

On moving a charge of \( 20 \, \text{C} \) by \( 2 \, \text{cm} \), 2 J of work is done, then the potential difference between the points is:

A potentiometer is connected across A and B, and a balance is obtained at 64.0 cm. When potentiometer lead to B is moved to C, a balance is found at 8.0 cm. If the potentiometer is now connected across B and C, a balance will be found at:

The insulation property of air breaks down at \( 3 \times 10^6 \, \text{V/m} \). The maximum charge that can be given to a sphere of diameter 5 m is nearly:

As shown in the figure, charges \( +q \) and \( -q \) are placed at the vertices B and C of an isosceles triangle. The potential at the vertex A is: