NEET Physics Class 12 Questions

Figure below show regular hexagons, with charges at the vertices. In which case, the electric field at the centre zero?

Time taken by sunlight to pass through a window of thickness 4 mm whose refractive index is 3/2 is

Match the Column I (electric lines of force) with Column II (types of charge) and select the correct answer from the codes given below.

A galvanometer of resistance 100 Ω gives full scale deflection for a current of 1.0 mA. It is converted into an ammeter of range 0-1 Å. The resistance of the ammeter will be close to

Temperature dependence of resistivity ρ(T) of semiconductors, insulators and metals is significantly based on the following factors : (1) number of charge carriers can change with temperature T (2) time interval between two successive collisions can depend on T.

In figure given below, assuming the diodes to be ideal

The energy of a photon of light of wavelength 450 nₘ is

The magnetic energy stored in an inductor of inductance 4μH carrying a current of 2A is

The dimensions of magnetic flux are

When light propagates through a material When light propagate permittivity εᵣ and relative medium of relative the velocity of light, v is given permeability μᵣ, the light in vacuum) by: (c = velocity of light in vacuum)

A wheatstone bridge is used to determine the value of unknown resistance X by adjusting the variable resistance Y as shown in the figure. For the most precise measurement of X, the resistances P and Q :

A point object is kept 60 cm in front of a spherical convex surface (μ = 1.5, radius of curvature 40 cm). The image formed is

The flux linked with a circuit is given by ϕB = t² + 2. The graph between time (X⁻axis) and induced emf (Y⁻axis) will be a

Which of the following correctly represents the variation of electric potential (V) of a charged spherical conductor of radius (R) with radial distance (r) from the centre?

A cell having an emf ε and internal resistance r is connected across a variable external resistance R. As the resistance R is increased, the plot of potential difference V across R is given by

Two conductors are made of the same material and have the same length. Conductor A is solid wire of diameter 1 mm. Conductor B is hollow tube of outer diameter 2 mm and inner diameter 1 mm. The ratio of resistance RA to RB.

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Alloys such as constantan and manganin are used in making standard resistance coils. Reason R: Constantan and manganin have very small value of temperature coefficient of resistance. In the light of the above statements, choose the correct answer from the options given below.

The critical angle for a ray of light passing from glass to water is minimum for

In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor

The resistance of a wire is 10 Ω. Its length is increased by 10% by stretching. The new resistance will now be

Match List I with List II:

Given below are two statements: Statement I : The equivalent resistance of resistors in a series combination is smaller than least resistance used in the combination. Statement II : The resistivity of the material is independent of temperature. In the light of the above statements, choose the correct answer from the options given below:

The current in the given circuit is

A battery supplies 0.9 Å current through a 2 Ω resistor and 0.3 Å current through a 7 Ω resistor when connected one by one. The internal resistance of the battery is

The range of voltmeter of resistance 300 \(\Omega\) is 5 V. The resistance to be connected to convert it into an ammeter of range 5 Å is

The resistor of resistance 'R' is connected to 25 V supply and heat produced in it is 25 J/sec. The value of R is

Two coils are placed near each other. When the current in one coil is changed at the rate of 5 A/s, an emf of 2 mV is induced in the other. The mutual inductance of the two coils is

Considering a group of positive charges, which of the following statements is correct?

Identify the correct statements from the following descriptions of various properties of electromagnetic waves. A. In a plane electromagnetic wave electric field and magnetic field must be perpendicular to each other and direction of propagation of wave should be along electric field or magnetic field. B. The energy in electromagnetic wave is divided equally between electric and magnetic fields.

The critical angle of a certain medium is sin⁻¹(3/5). The polarizing angle of the medium is

If μ₀ = permeability of free space & ε₀ = permittivity of free space. Find the value of μ₀ε₀.

Beams of electrons and protons move parallel to each other in the same direction. They

Statement 1: No work is required to be done to move a test charge between any two points on an equipotential surface. Statement 2: Electric lines of force at the equipotential surfaces are mutually perpendicular to each other.

A metallic rod of length 'L' is rotated with an angular speed of 'ω' normal to a uniform magnetic field 'B' about an axis passing through one end of rod as shown in figure. The induced emf will be:

The energy density associated with electric field E̅ and magnetic field B̅ of an electromagnetic wave in free space is given by (ε₀ - permittivity of free space, μ₀ permeability of free space)

In a double slit experiment the angular width of a fringe is found to be 0.2° on a screen placed 1 m away. The wavelength of light used is 600 nₘ. The angular width of the fringe if entire experimental apparatus is immersed in water, is Take μ_water = 4/3

A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 × 10⁸ ms⁻¹ and 230 nₘ respectively. The wavelength of light in air will be.

Dimensional formula of mutual inductance is

A transformer is used to light 140 W, 24 V lamp from 240 V ac mains. If the main current is 0.7 Å, the efficiency of the transformer is

An equiconvex lens is cut into two halves along (i) XOX and (ii) YOY as shown in the figure. Let f, f', f'' be the focal lengths of the complete lens, of each half in case (i), and of each half in case (ii) respectively. Choose the correct statement from the following:

A vessel of depth 'd' is half filled with oil of refractive index n₁ and the other half is filled with water of refractive index n₂. The apparent depth of this vessel when viewed from above will be-

An electromagnetic wave propagating along north has its electric field vector upwards. Its magnetic field vector point towards

Lenz's law is consequence of the law of conservation of

A light bulb and an open coil induction are connected in series to an ac source as shown in figure. Now an iron rod is inserted into the interior of the inductor. The glow of the light bulb

The interference pattern is obtained with two coherent light sources of intensity ratio n. In the interference pattern, the ratio \( \frac{I_{\text{max}} - I_{\text{min}}}{I_{\text{max}} + I_{\text{min}}} \) will be:

A square of side L metres lies in the xy-plane in a region, where the magnetic field is given by B = B₀(2î + 3ĵ + 4k̂)T, where B₀ is constant. The magnitude of flux passing through the square is

A copper ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet while it is passing through the ring is

Light travels in two media M₁ and M₂ with speeds 1.5 × 10⁸ m s⁻¹ and 2.0 × 10⁸ m s⁻¹ respectively. The critical angle between them is:

The direction of ray of light incident on a concave mirror is shown by PQ while directions in which the ray would travel after reflection is shown by four rays marked 1, 2, 3 and 4 (figure). Which of the four rays correctly shows the direction of reflected ray?

A convex lens of focal length 80 cm and a concave lens of focal length 50 cm are combined together. What will be their resulting power?