G11 T2 Quiz 1 Reflection And Refraction

Explanation
Based on the figure shown in the mirror, the girl appears to be holding the brush with her right hand.

Explanation
When light travels from air into glass, it undergoes refraction, which means that the direction of the light waves changes. This change in direction occurs because the speed of light is different in air compared to glass. As light enters the denser medium of glass, its speed decreases, causing it to bend or change direction. Therefore, the correct answer is that the speed of the light changes.

Explanation
The diagram shows a ray of light entering a block of glass. The angle of incidence is the angle at which the ray of light enters the glass, and it is labeled as angle 2 in the diagram. The angle of refraction is the angle at which the ray of light bends as it passes through the glass, and it is labeled as angle 4 in the diagram. Therefore, the correct answer is "Incidence:2; refraction: 4".

Explanation
Diagram A correctly shows a ray of light passing through a rectangular glass block because the ray enters the block at an angle, bends towards the normal, and then exits the block parallel to its original direction. This is consistent with the principles of refraction, where light bends when it travels from one medium to another with a different refractive index. Diagrams B, C, and D do not accurately depict the bending of light when passing through a rectangular glass block.

Explanation
When light from the Sun passes through a prism, it gets separated into its different wavelengths, forming a spectrum on a screen. The fact that a thermometer placed at P shows a large temperature rise suggests that the type of radiation causing this is infra-red. Infra-red radiation has longer wavelengths and carries more heat energy compared to visible light, ultraviolet, or microwave radiation. Therefore, it is able to cause a significant temperature rise when absorbed by the thermometer.

Explanation
When the angle of incidence is greater than the critical angle, total internal reflection occurs. This means that the light ray is reflected back into the glass instead of being refracted out of it. Therefore, the correct arrow to show the direction of the ray after it leaves the edge of the glass is D, which indicates that the ray is reflected back into the glass.

Explanation
Light travels in straight lines, so the only possible path for light from the stone at the bottom of the pool to the man would be path B.

Explanation
The angle of refraction can be calculated using Snell's Law, which states that the ratio of the sines of the angles of incidence and refraction is equal to the ratio of the indices of refraction of the two media. In this case, the angle of incidence is 30 degrees and the index of refraction of glass is 1.5. By applying Snell's Law, we can find that the angle of refraction is 19.5 degrees.

Explanation
The index of refraction for a medium is defined as the ratio of the speed of light in a vacuum to the speed of light in that medium. In this case, the speed of light in air is almost 3x10^8 m/s, and in the glass, it slows down to 2x10^8 m/s. By dividing the speed of light in a vacuum by the speed of light in the glass, we get an index of refraction of 1.5.

Explanation
The critical angle of a medium is the angle of incidence at which the refracted ray is at 90 degrees from the normal. In this case, the correct answer is 43 because it is the only option that is less than 90 degrees.