Physics

In the photoelectric effect, the kinetic energy of emitted electrons depends on the frequency (or wavelength) of the incident light, not its intensity. Increasing the intensity increases the number of emitted electrons but does not change their kinetic energy, which remains the same if the wavelength is unchanged.

In simple harmonic motion (SHM), the total mechanical energy remains constant throughout the motion. This total energy is the sum of kinetic energy and potential energy. The kinetic energy is maximum at the mean (equilibrium) position where the velocity is highest, and the potential energy is maximum at the extreme positions where the displacement is maximum and velocity is zero. Since total energy is conserved and constant at all positions during SHM, it is not maximum at any particular position but remains the same throughout the motion. Therefore, the correct answer is that the energy of SHM is maximum at all positions during SHM.

When an object is placed beyond 2f (twice the focal length) of a converging lens, the image formed is real, inverted, and smaller than the object. This is a fundamental property of convex lenses.

The Compton effect demonstrates that light behaves as particles called photons, as it shows X-rays scattering off electrons with a change in wavelength consistent with particle collisions, thus proving the photon theory of light.

Magnification (M) is calculated as the ratio of the image height to the object height: M = image height / object height. Here, the object height is 5 mm and the image height is 1 cm, which is 10 mm. Therefore, magnification M = 10 mm / 5 mm = 2. This means the image is twice the size of the object, so the correct answer is D (2).

Energetic particles in an electron microscope have high kinetic energy, which gives them a very short wavelength and high penetrating power. All these factors contribute to the improved resolution and imaging capability of electron microscopes.

A photon is defined as a quantum of electromagnetic radiation, meaning it is the smallest discrete amount or packet of electromagnetic energy. It is not a unit of energy, a charged particle, or a unit of wavelength.

Michelson's formula for calculating the speed of light is C = 8fd, where f is the frequency of the rotating mirror and d is the distance to the fixed mirror. This formula arises from the time taken for light to travel to the mirror and back, combined with the angular displacement of the rotating mirror.

A seconds pendulum has a time period of 2 seconds. Using the formula T = 2π√(L/g), and taking g ≈ 9.8 m/s², the calculated length comes out to approximately 99.2 cm. Hence, option C is correct.

In a normal adjustment of an astronomical telescope, the length of the telescope is equal to the sum of the focal lengths of the objective lens (fo) and the eyepiece (fe), i.e., length = fo + fe. This arrangement ensures the final image is at infinity, allowing comfortable viewing.