Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Physics

In what respect is a toroid different from a solenoid? 

 Draw and compare the pattern of the magnetic field lines in the two cases ?

How is the magnetic field inside a given solenoid made strong?

Calculate the speed of light in a medium whose critical angle is 30° ?

Plot a graph showing the variation of stopping potential with the frequency of incident radiation for two different photosensitive materials having work functions W₁ and W₂ (W₁ > W₂). On what factors does the (i) slope and (ii) intercept of the lines depend?

The energy levels of an atom are as shown below. Which of them will result in the transition of a photon of wavelength 275 nm?

Which transition corresponds to emission of radiation of maximum wavelength?

Draw a circuit diagram to study the input and output characteristics of an n-p-n transistor in its common emitter configuration. Draw the typical input and output characteristics.

Explain, with the help of a circuit diagram, the working of n-p-n transistor as a common emitter amplifier.

How is a zener diode fabricated so as to make it a special purpose diode? Draw I-V characteristics of zener diode and explain the significance of breakdown voltage.

Explain briefly, with the help of a circuit diagram, how a p-n junction diode works as a half wave rectifier.

Can we perform Young's double slit experiment with sound waves? To get a reasonable "fringe pattern", what should be the order of separation between the slits? How can the bright fringes and the dark fringes be detected in this case?

If the separation between the slits in a Young's double slit experiment is increased, what happens to the fringe-width? If the separation is increased too much, will the fringe pattern remain detectable?

Suppose white light falls on a double slit but one slit is covered by a violet filter (allowing λ = 400 nm). Describe the nature of the fringe pattern observed.

The slits in a Young's double slit experiment have equal width and the source is placed symmetrically with respect to the slits. The intensity at the central fringe is I₀. If one of the slits is closed, the intensity at this point will be ____________ .

A thin transparent sheet is placed in front of a Young's double slit. The fringe-width will _____________ .

If Young's double slit experiment is performed in water, _________________ .

If the source of light used in a Young's double slit experiment is changed from red to violet, ___________ .

A Young's double slit experiment is performed with white light.

(a) The central fringe will be white.

(b) There will not be a completely dark fringe.

(c) The fringe next to the central will be red.

(d) The fringe next to the central will be violet.

The separation between the consecutive dark fringes in a Young's double slit experiment is 1.0 mm. The screen is placed at a distance of 2.5m from the slits and the separation between the slits is 1.0 mm. Calculate the wavelength of light used for the experiment.

In a double slit interference experiment, the separation between the slits is 1.0 mm, the wavelength of light used is 5.0 × 10⁻⁷ m and the distance of the screen from the slits is 1.0m. (a) Find the distance of the centre of the first minimum from the centre of the central maximum. (b) How many bright fringes are formed in one centimetre width on the screen?