Physics

When light is incident normally on a thin film, the path difference between the reflected rays depends on the thickness of the film, the refractive index (nature) of the film, and the angle of incidence. However, at normal incidence, the angle of incidence is zero, so it does not affect the path difference. The path difference is given by 2 * thickness * refractive index of the film. Therefore, the path difference depends on both the thickness and the nature (refractive index) of the film. Since the angle of incidence is zero, it does not contribute, but the question's options do not separate thickness and nature clearly. The best correct choice is that the path difference depends on all three factors (thickness, nature, and angle), but practically at normal incidence, angle is zero and does not affect it. Hence, option D is the most accurate answer given the options.

Jupiter has the highest escape velocity among the planets in the solar system due to its large mass and size, which creates a stronger gravitational pull compared to other planets.

Stress, Young's modulus, and pressure all have the dimensions of force per unit area (N/m² or Pascal). Strain, however, is a dimensionless quantity representing deformation relative to original length, so it does not have dimensions of force per unit area.

Stress is defined as force per unit area. Force has dimensions MLT⁻² and area has dimensions L², so stress dimensions are MLT⁻² divided by L², which simplifies to ML⁻¹T⁻².

Isotropy refers to the property of being identical in all directions, meaning the density of atoms remains the same along any direction in a crystal. Homogeneity means uniform composition throughout but does not specifically imply directional uniformity.

Einstein proposed that light travels as discrete packets of energy called photons, which explained the photoelectric effect. This concept established the particle nature of light alongside its wave properties.

A blue book appears blue because it reflects blue light. Under monochromatic red light, there is no blue light to reflect, so the book absorbs the red light and appears black.

In the double slit experiment, covering one slit removes the possibility of interference between two coherent sources, so no interference fringes are observed. However, diffraction from the single open slit still occurs, so diffraction fringes can be seen.

An object that emits its own light is called luminous. Non-luminous objects do not produce their own light, incandescent refers to emitting light due to heat, and bright describes the intensity of light, not the source.

Momentum is directly proportional to velocity, so doubling velocity doubles momentum. Kinetic energy is proportional to the square of velocity, so doubling velocity increases kinetic energy by four times.