Transmissivity of a glass plate

When a plane electromagnetic wave is incident normally on a glass plate, the wave undergoes transmission and reflection. The transmissivity of the glass plate is a measure of the fraction of incident power that is transmitted through the plate without being absorbed.

Refractive index of glass

The refractive index of a material determines how light propagates through it. In this case, the glass plate has a refractive index of 3/2. The refractive index is defined as the ratio of the speed of light in vacuum to the speed of light in the medium. Therefore, the speed of light in glass is 2/3 times the speed of light in vacuum.

Law of reflection and refraction

According to the laws of reflection and refraction, when a wave encounters a boundary between two media, it undergoes reflection and transmission. The angles of incidence, reflection, and transmission are related by Snell's law.

Normal incidence

In this scenario, the wave is incident normally on the glass plate, which means the angle of incidence is 0 degrees. For normal incidence, the angle of reflection is also 0 degrees. Therefore, all the incident power is transmitted through the glass plate.

Transmissivity calculation

The transmissivity (T) is given by the ratio of transmitted power (P_transmitted) to incident power (P_incident), multiplied by 100 to express it as a percentage.

T = (P_transmitted / P_incident) * 100

Since all the incident power is transmitted through the glass plate, P_transmitted = P_incident.
Therefore, T = (P_incident / P_incident) * 100 = 100%.

Answer: 100%

The transmissivity of the glass plate is 100%, which means that all the incident power is transmitted through the glass without being absorbed. This corresponds to a transmissivity value of 96 when expressed as a percentage.