List of top Physics Questions

The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of width 0.2 mm is focused on the focal plane of a convex lens of focal length 100 cm. The width of the 1st secondary maxima will be :

A proton is taken from point P1 to point P2, both located in an electric field. The potentials at points P1 and P2 are -5 V and +5 V respectively. Assuming that kinetic energies of the proton at points P1 and P2 are zero, the work done on the proton is:

Figure shows a part of an electric circuit. The potentials at points $ a, b, \text{and} \, c $ are $ 30 \, \text{V}, 12 \, \text{V}, \, \text{and} \, 2 \, \text{V} $, respectively. The current through the $ 20 \, \Omega $ resistor will be:

The above two parts are kept in contact with each other as shown in the figure. The power of the combination will be:

A simple pendulum of length 1 m has a wooden bob of mass 1 kg. It is struck by a bullet of mass 10^–2 kg moving with a speed of 2 × 10² ms^–1 . The bullet gets embedded into the bob. The height to which the bob rises before swinging back is. (use g = 10 ms^-2 )

Three point charges, 1 pC each, are kept at the vertices of an equilateral triangle of side 10 cm. Find the net electric field at the centroid of the triangle.

In a p-type semiconductor, the acceptor level is situated 50 meV above the valence band. The maximum wavelength of light required to produce a hole will be:

The study of radioactive decay results in the emission of particles, leading to four observations: (A) No change in atomic and mass number, (B) Atomic number decreases by 1, (C) Study of radioactive decay of unstable nuclei resulting in emission of a
particle leads us to four different observations listed below:
(A) Nochange in atomic number and mass number.
(B) Nochange in mass number but the atomic number decreases by 1.
(C) Nochange in mass number but the atomic number increases by 1.
(D) Atomic number decreases by 2 and the mass number decreases by 4.
Arrange the particles emitted in the above four cases in correct sequence:

A long solenoid is formed by winding insulated copper wire at the rate of 20 turns per cm. The current required to produce a magnetic field of 20 mT inside the solenoid at its center would be:

The Wheatstone bridge is an arrangement of four resistances, say $R_1, R_2, R_3$, and $R_4$. The null point condition is given by:

Two parallel plate capacitors, each of capacitance 40 µF, are connected in series. The space between the plates of one capacitor is filled with a material of dielectric constant K = 4. The equivalent capacitance of the system would be:

When a photon of energy hν falls on a photosensitive metallic surface (work function hν0), electrons are emitted from the metallic surface. It is possible to say that:

An equilateral prism is made of material of refractive index $\sqrt{3}$. The angle of minimum deviation through the prism is:

As per Nuclear Physics, there is a close relationship between mass num ber and radius of the nucleus. If the mass number of A is 216 and the mass number of B is 27, then the ratio of nuclear radius $\frac{r_A}{r_B}$ of the two elements is:

Consider the following particles:
(A) Proton,
(B) α-particle,
(C) Electron.
For charge to mass ratio of the above particles, we can say:

If the momentum of an electron is changed by P, then the de Broglie wavelength associated with it changes by $1\%$. The initial momentum of the electron will be:

If the energy of incident radiation is increased by $25\%$, the kinetic energy of the photoelectrons emitted increases from 0.6 eV to 0.9 eV. The work function of the metal is:

For a light pipe as shown in the figure:

(A) Optical density of core should be greater than the optical density of cladding.
(B) r and θ will always be equal.
(C) Optical density of cladding is $\frac{sinθ sin i}{sin r}$.
(D) Optical density of cladding is $\frac{sin r sin i }{sin θ}.$
Choose the correct answer from the options given below:

Read the following:
(A) The width of the central band in a diffraction pattern.
(B) The width of the first bright band in the diffraction pattern.
(C) The width of the central band in the diffraction pattern if D is doubled.
(D) The width of the first bright band in the diffraction pattern if D is tripled.
Choose the correct answer from the options given below in increasing order of width.

Light from a point source in air falls on a spherical glass surface (n = 1.5, radius of curvature = 10cm). The distance of the light source from the glass surface is 50 cm. The position at which the image is formed is:

$\text{ Arrange the following in increasing order of focal length of convex lens:}$
$(A)$ $F_v$, focal lengths of violet
$(B)$ $F_r$, focal lengths of red
$(C)$ $F_b$, focal lengths of blue
$(D)$ $F_y$, focal lengths of yellow
$\text{Choose the correct answer from the options given below:}$

$ \text{ The electric field of an EM wave in free space is given by } E = 10 \cos(10^7 t + kx) \, \hat{j} \, \text{V/m, where } t \text{ and } x \text{ are in seconds and meters, respectively. It can be inferred that:}$
Which of the following pairs of statements are correct:
(A) Wavelength λ is 188.4 m,
(B) Wave number k is 0.33 rad/m,
(C) Wave amplitude is 10 V/m,
(D) Wave is propagating along +x-direction.

For a series LCR circuit, at the condition of resonance, the value of the power factor will be:

In an LCR series circuit, the source of emf is E=30sin(100t), R=120Ω, L=100mH, C=100μF.
(A) The numerical value of impedance
(B) The numerical value of resistance R
(C) The numerical value of capacitive reactance
(D) The numerical value of inductive reactance.
Arrange the values of quantities mentioned in (A, B, C, D) in increasing order.

A capacitor and a coil with resistance R are in series and connected to a 6 V AC source. By varying the frequency of the source, a maximum current of 600 mA is observed. If the same coil is now connected to a cell of emf 6 V and internal resistance of 2 ohms, the current through it will be: