List of top Physics Questions asked in NEET (UG)

A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices $\mu_1$ and $\mu_2$ and $R$ is the radius of curvature of the curved surface of the lenses, then the focal length of combination is

In Young's double slit experiment, the slits are 2mm apart and are illuminated by photons of two wavelengths $\lambda_1 = 12000 \mathring A $ and $\lambda_2 = 10000 \mathring A.$ At what minimum distance from the common central bright fringe on the screen 2m from the slit will a bright fringe from one interference pattern coincide with a bright fringe from the other ?

A coil is self-inductance $L$ is connected in series with a bulb $B$ and an $AC$ source. Brightness of the bulb decreases when :

Two metal rods $1$ and $2$ of same lengths have same temperature difference between their ends. Their thermal conductivities are $ K_1$ and $K_2 $ and cross sectional areas $ A_1 $ and $ A_ 2 $ respectively. If the rate of heat conduction in 1 is four times that in 2, then :

For a normal eye, the cornea of eye provides a converging power of $40\, D$ and the least converging power of the eye lens behind the cornea is $20\, D$. Using this information, the distance between the retina and the cornea -eye lens can be estimated to be -

A system is taken from state $a$ to state $c$ by two paths $adc$ and $abc$ as shown in the figure. The internal energy at $a$ is $U_a=10 \, J . $ Along the path $adc$ the amount of heat heat absorbed $\delta Q_1=50\, J $ and the work obtained $\delta W_1=20 \, J $ whereas along the path $abc$ the heat absorbed $\delta Q_2=36 \, J . $ The amount of work along the path $abc$ is :

The condition under which a microwave oven heats up a food item containing water molecules most efficiently is :

A wire loop is rotated in magnetic field. The frequency of change of direction of the induced e.m.f. is :

A particle of mass $m$ is kept at rest at a height $3R$ from the surface of earth, where $R$ is radius of earth and $M$ is mass of earth. The minimum speed with which it should be projected, so that it does not return back, is : (g is acceleration due to gravity on the surface of earth)

A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using :

The radius of a planet is twice the radius of earth. Both have almost equal average mass-densities. $v_P$ and $v_E$ are escape velocities of the planet and the earth, respectively, then

A wire of resistance $4 \, \Omega$ is stretched to twice its original length. The resistance of stretched wire would be :

A bar magnet of length '$l$' and magnetic dipole moment 'M' is bent in the form of an arc as shown in figure. The new magnetic dipole moment will be

A current loop in a magnetic field :

In which of the following statements, the obtained impure semiconductor is of $p$-type ?

An electric dipole of dipole moment $p$ is aligned parallel to a uniform electric field $E$. The energy required to rotate the dipole by $ 90^\circ $ is :

The resistances of the four arms $P,Q, R$ and $S$ in a Wheatstone's bridge are 10 ohm, 30 ohm, 30 ohm and 90 ohm, respectively. The e.m.f. and internal resistance of the cell are 7 volt and 5 ohm respectively. If the galvanometer resistance is 50 ohm, the current drawn from the cell will be :

In an unbiased $p-n$ junction, holes diffuse from the $p$-region to $n$-region because of

A wave travelling in the $+ve$ $x-direction$ having displacement along $y$-direction as $1m$, wavelength $2 \pi m$ and frequency of $ \frac{1}{\pi} Hz$ is represented by :

A uniform force of $(3 \hat{i} + \hat{j})$ newton acts on a particle of mass 2kg. Hence the particle is displaced from position$ (2\hat{i} + \hat{k} )$ meter to position $(4\hat{i} + 3\hat{j} - \hat{k})$ meter. The work done by the force on the particle is :

In a common emitter $(CE)$ amplifier having a voltage gain $G$, the transistor used has transconductance $0.03 \,mho$ and current gain $25$. If the above transistor is replaced with another one with transconductance $0.02$ $mho$ and current gain $20$, the voltage gain will be :

The wavelength $\lambda_e$ of an electron and $\lambda_P$ of a photon of same energy E are related by:

When a proton is released from rest in a room, it starts with an initial acceleration $a_0$ towards west. When it is projected towards north with a speed $v_0$ it moves with an initial acceleration $3a_0$ towards west. The electric and magnetic fields in the room are:

Infinite number of bodies, each of mass 2 kg are situated on x-axis at distance 1m, 2m, 4m, 8m, ...., respectively, from the origin. The resulting gravitational potential due to this system at the origin will be