List of top Physics Questions

Two point charges +4µC and -2µC are placed at a certain distance in air. They experience an attractive force F. If they are brought in contact with each other and then separated to the same distance, the new repulsive force between them will be :

Which of the following is/are responsible for the formation of Rainbow?
(A) Dispersion of light
(B) Interference of light
(C) Reflection of light
(D) Refraction of light
Choose the correct answer from the options given below:

Which of the following statements are correct?
(A) The resistivity of a semiconductor decreases with increasing temperature.
(B) The potentiometer is unaffected by the internal resistance of the source.
(C) In ionic crystals and electrolytic liquids electrons carry the electric current.
(D) Ohm's law fails if V depends on I non-linearly.
(E) Kirchhoff's rules are used for analysis of electric circuits.
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Two charges 5 µC and -2 µC (with no external field) are placed at (-9 cm, 0, 0) and (9 cm, 0, 0) respectively. The work required to separate the two charges infinitely away from each other is :

The capacitance of capacitor increases when :
(A) its charge increases
(B) its supply voltage decreases
(C) common area of the plates increases
(D) separation between the plates decreases
Choose the correct answer

A vertical electric field of magnitude 4.9×10⁵ NC^-1 just prevents a water droplet of mass 0.1 g from falling. What is the charge on the droplet? Take acceleration due to gravity 9.8 ms^-2.

The logic gate realised using p-n junction diodes in the given figure is:

Who among the following in Ancient India made some prominent discoveries in Physics?

C.V. Raman got Nobel Prize in 1930 for his discovery of:

Match LIST I with LIST II

LIST I Device		LIST II  Purpose
A	Microphone	I	Used in vehicles to measure distance
B	Audiometer	II	For measuring the force and velocity of wind
C	Odometer	III	Converts sound waves to electrical vibrations
D	Anemometer	IV	Measures intensity of sound

Choose the most appropriate answer from the options given below:

The correct mathematical expression for amplitude modulated wave is:

Let us consider interference between two sources of intensities I and 4I. What will be the intensity at points where the phase difference is π?

For a medium with permittivity (e) and permeability (µ), the speed of light (v) is given by:

A spherical conducting shell of inner radius r₁ and outer radius r₂ has a charge Q. A charge q is placed at the centre of the shell. The surface charge density on outer surface of the shell is:

Electron and Photon have same de Broglie wavelength, which of the following is true for their momentum:

A parallel beam of monochromatic light of wavelength 460 nm passes through a long slit of width 0.1 mm. What is the angular divergence in which most of the light is diffracted?

Two polaroid P₁ and P₃ are placed such that their pass-axis are mutually perpendicular. Another polaroid P₂ is rotated between P₁ and P₃. For what angle θ between P₁ and P₂ the intensity of light emerging from P₃ will be maximum?

The potential of a uniformly charged spherical shell at a point r/2 from its centre is 5 V. The potential at its surface is:
(Given radius of shell = r)

Choose the correct statements:
(A) A nuclide is represented as \(^Z_AX\)
(B) Nuclids with same number of protons are called isotopes
(C) a-ray scattering experiments allow determination of the nuclear radius
(D) Nuclids with same number of neutrons are called isotones
(E) The nuclear force distinguishes between neutron and proton
Choose the correct answer from the options given below:

Consider two different hydrogen atoms. The electron in each atom is in first excited state. According to Bohr's model, electrons will have:

An infinite line charge produces an electric field of 9 × 10⁶ N/C at a distance of 20 cm. The linear charge density will be :

Match List I with List II

List-I		List-II
(A)	To slow down fast moving neutrons	(I)	Thermal neutrons
(B)	A neutron or a proton	(II)	Fission
(C)	Slow neutrons	(III)	Moderator
(D)	Neutron induced nuclear reaction	(IV)	Nucleon

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Energy band gap is maximum in:

The shape of graph between 1/u and 1/v in case of a convex lens is:

Which of the following graph correctly shows the relation between photoelectric current (I) and wavelength (λ) of incident radiation