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M → \(\frac{Hi}{Ho}\) = \(\frac{Di}{Do}\) where M is the magnification, Hi is the height of the image, Ho is the height of the object, Di is the distance from the lens to the in-focus projected image, and Do is the distance from the object to the lens. But Di = \(\frac{Hi * Do}{Ho}\) → \(\frac{20 * 30}{40}\) Image distance(Di) = 15cm

Fiber optic couplers are used to split the input signals into two or more outputs, they are called splitters in this case. On the other hand, some types of couplers can be used to combine two or more inputs into one single output, they are called combiners in this case.

Eclipse of the moon occurs when the earth comes between the sun and the moon.

The power of a lens is defined as the reciprocal of its focal length in metres: P = \(\frac{100}{f}\) → 2.5 = \(\frac{100}{f}\) where P is the power in diopters and f is the focal length in metres. 2.5 * f = 100 f = \(\frac{100}{2.5}\) f = 40 Where f = \(\frac{r}{2}\) radius of the curvature[r] = f * 2 → 40 * 2 r = 80cm

Refraction occurs when light travels from one medium to another which changes the speed at which the light travels. This causes light to bend upon incidence with the interface of a new material. Angle of refraction is smaller than angle of incidence when light ray travels from rarer medium to denser medium. I.e light can either refract towards the normal(when slowing down while crossing the boundary) or away from the normal (when speeding up while crossing the boundary). When light undergoes refraction, its frequency remains the same.

A mechanical wave is a wave that is an oscillation of matter. A sound wave is a mechanical wave that propagates along or through a medium by particle-to-particle interaction. Sound waves, water waves and seismic waves are some examples of mechanical waves mechanical wave.

The relation between period and frequency is that one is the inverse of the other. By definition: Frequency = 1/period. or period = 1/frequency → 1/ 10,000 period = 0.0001 or 1.0 x 10\(^{-4}\) s

In physics, a transverse wave is a wave whose oscillations are perpendicular to the direction of the wave's advance. This is in contrast to a longitudinal wave which travels in the direction of its oscillations. Water waves are an example of transverse wave.

All electromagnetic waves are: transverse waves; can travel through a vacuum ; travel at exactly the same speed in a vacuum, the speed of light, 300,000,000 m/s. transfer energy from one place to another; can be reflected; can be refracted . The oscillations of and are perpendicular to each other and are in the same phase.

The angular wave number k = \(\frac{2\pi}{\lambda}\) expresses the number of radians in a unit of distance.

beat, in physics, the pulsation caused by the combination of two waves of slightly different frequencies.

speed of the sound wave = \(\frac{distance * 2}{time}\) = \(\frac{408 * 2}{2.4}\) : speed of the sound wave = 340 ms\(^{-1}\)

v = f \lambda to calculate the wave's velocity. v = 312 x 1.10 = 343.2m/s

Factors Affecting The Speed of Sound The Density of Medium: Sound requires a medium to travel. The density of the medium is among the factors which affect the speed of sound. ... The Temperature of The Medium: Higher the temperature, the higher is the speed of sound in the medium.

For a converging lens to act as a simple microscope, the object must be placed at a distance less than one focal length.