PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Physics

In a Young's double slit experiment, the separation between the slits = 2.0 mm, the wavelength of the light = 600 nm and the distance of the screen from the slits = 2.0 m. If the intensity at the centre of the central maximum is 0.20 W m⁻², what will be the intensity at a point 0.5 cm away from this centre along the width of the fringes?

In a Young's double slit interference experiment, the fringe pattern is observed on a screen placed at a distance D from the slits. The slits are separated by a distance d and are illuminated by monochromatic light of wavelength \[\lambda.\] Find the distance from the central point where the intensity falls to (a) half the maximum, (b) one-fourth the maximum.

In a Young's double slit experiment, \[\lambda = 500\text{ nm, d = 1.0 mm and D = 1.0 m.}\] Find the minimum distance from the central maximum for which the intensity is half of the maximum intensity.

The line-width of a bright fringe is sometimes defined as the separation between the points on the two sides of the central line where the intensity falls to half the maximum. Find the line-width of a bright fringe in a Young's double slit experiment in terms of \[\lambda,\] d and D where the symbols have their usual meanings.

Total internal reflection can take place only if ______.

Consider the arrangement shown in the figure. By some mechanism, the separation between the slits S₃ and S₄ can be changed. The intensity is measured at the point P, which is at the common perpendicular bisector of S₁S₂ and S₂S₄. When \[z = \frac{D\lambda}{2d},\] the intensity measured at P is I. Find the intensity when z is equal to

(a) \[\frac{D\lambda}{d}\]

(b) \[\frac{3D\lambda}{2d}\]  and

(c) \[\frac{2D\lambda}{d}\]

The charge on a proton is +1.6 × 10⁻¹⁹ C and that on an electron is −1.6 × 10⁻¹⁹ C. Does it mean that the electron has 3.2 × 10⁻¹⁹ C less charge than the proton? 

When the separation between two charges is increased, the electric potential energy of the charges

The electric field at the origin is along the positive x-axis. A small circle is drawn with the centre at the origin, cutting the axes at points A, B, C and D with coordinates (a, 0), (0, a), (−a, 0), (0, −a), respectively. Out of the points on the periphery of the circle, the potential is minimum at  

If a body is charged by rubbing it, its weight

Consider the situation in the figure. The work done in taking a point charge from P to Ais W_A, from P to B is W_B and from P to C is W_C. 

A point charge q is rotated along a circle in an electric field generated by another point charge Q. The work done by the electric field on the rotating charge in one complete revolution is 

The electric field and the electric potential at a point are E and V, respectively.  

Electric potential decreases uniformly from 120 V to 80 V, as one moves on the x-axis from x = −1 cm to x = +1 cm. The electric field at the origin 

(a) must be equal to 20 Vcm⁻¹
(b) may be equal to 20 Vcm⁻¹
(c) may be greater than 20 Vcm⁻¹
(d) may be less than 20 Vcm⁻¹ 

Which of the following quantities does not depend on the choice of zero potential or zero potential energy?

The electric field in a region is directed outward and is proportional to the distance rfrom the origin. Taking the electric potential at the origin to be zero,