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

Define the term 'electrical conductivity' of a metallic wire. Write its S.I. unit.

Figure shows a ray of light passing through a prism. If the refracted ray QR is parallel to the base BC, show that (i) r₁ = r₂ = A/2 and (ii) angle of minimum deviation, D_m = 2i − A.

Draw a plot of potential energy between a pair of nucleons as a function of their separation. Mark the regions where potential energy is (i) positive and (ii) negative.

Why should electrostatic field be zero inside a conductor?

How does the angular separation between fringes in single-slit diffraction experiment change when the distance of separation between the slit screens is doubled?

 Out of blue and red light which is deviated more by a prism? Give reason.

Give the formula that can be used to determine refractive index of materials of a prism in minimum deviation condition ?

Draw a plot of potential energy of a pair of nucleons as a function of their separation.

what is the significance of negative potential energy in the graph drawn?

When a drop of oil is spread on a water surface, it displays beautiful colours in daylight because of ______________ .

Four light waves are represented by

(i) \[y =  a_1   \sin  \omega t\]

(ii) \[y =  a_2   \sin  \left( \omega t + \epsilon \right)\]

(iii) \[y =  a_1   \sin  2\omega t\]

(iv) \[y =  a_2   \sin  2\left( \omega t + \epsilon \right).\]

Interference fringes may be observed due to superposition of

(a) (i) and (ii)

(b) (i) and (iii)

(c) (ii) and (iv)

(d) (iii) and (iv)

A narrow slit S transmitting light of wavelength λ is placed a distance d above a large plane mirror, as shown in the following figure. The light coming directly from the slit and that coming after the reflection interfere at a screen ∑ placed at a distance D from the slit. (a) What will be the intensity at a point just above the mirror, i.e. just above O? (b) At what distance from O does the first maximum occur?

A long narrow horizontal slit is paced 1 mm above a horizontal plane mirror. The interference between the light coming directly from the slit and that after reflection is seen on a screen 1.0 m away from the slit. Find the fringe-width if the light used has a wavelength of 700 nm.

A long narrow horizontal slit is paced 1 mm above a horizontal plane mirror. The interference between the light coming directly from the slit and that after reflection is seen on a screen 1.0 m away from the slit. If the mirror reflects only 64% of the light energy falling on it, what will be the ratio of the maximum to the minimum intensity in the interference pattern observed on the screen?

The equation \[\omega = \frac{\mu_u - \mu_r}{\mu - 1}\] was derived for a prism having small refracting angle. Is it also valid for a prism of large refracting angle? Is it also valid for a glass slab or a glass sphere?

Can the dispersive power \[\omega = \frac{\mu_u - \mu_r}{\mu - 1}\] be negative? What is the sign of ω if a hollow prism is immersed into water?

If three identical prisms are combined, is it possible to pass a beam that emerges undeviated? Undispersed?

The angular dispersion produced by a prism ___________ .

If a glass prism is dipped in water, its dispersive power ___________ .

A prism can produce a minimum deviation δ in a light beam. If three such prisms are combined, the minimum deviation that can be produced in this beam is _______________.

By properly combining two prisms made of different materials, it is possible to

(a) have dispersion without average deviation

(b) have deviation without dispersion

(c) have both dispersion and average deviation

(d) have neither dispersion nor average deviation