When a light travels from less dense medium to denser medium, the light will be refracted...

• ...towards normal.

• ...away from normal.

• ...towards the observer.

• ...away from the source.

When a light travels from denser medium to less dense medium, the light will be refracted...

• ...towards normal.

• ...away from normal.

• ...towards the observer.

• ...away from the source.

Light refraction occurs because...

• the speed and wavelength of the light change like those of any other refracted wave.

• the frequency and the speed of the light change like those of any other refracted wave,

• the frequency and the wavelength of the light change like those of any other refracted wave,

• it's the coolest wave in the universe.

which one is correct about convex lens and concave lens in terms of their effect on light rays.

• convex is diverging while concave is converging.

• convex is converging while concave is diverging.

• both of them are converging.

• both of them are diverging.

select two statements that make up the law of reflection.

• (sin i)/(sin r) = constant, where i is angle of incidence and r is angle of refraction.

• i = r, where i is angle of incidence and r is angle of reflection.

• incident ray, reflected ray and normal to the surface of reflection all lie on the same plane.

• incident ray, refracted ray and normal to the surface of reflection all lie on the same plane.

select two statements that make up the law of refraction.

• (sin i)/(sin r) = constant, where i is angle of incidence and r is angle of refraction.

• i = r, where i is angle of incidence and r is angle of reflection.

• incident ray, reflected ray and normal to the surface of reflection all lie on the same plane.

• incident ray, refracted ray and normal to the surface of reflection all lie on the same plane.

when the angle of incidence equals to critical angle of the medium, the angle of refraction equals to...

• ...45 degrees.

• ...180 degrees.

• ...90 degrees.

• ...0 degrees.

Which statement is true about red light compared to blue light?

• red light has longer wavelength and higher frequency than blue light.

• red light has longer wavelength and lower frequency than blue light.

• red light has shorter wavelength and higher frequency than blue light.

• red light has longer wavelength and lower frequency than blue light.

Blue light and red light both travel at the same speed in...

• ... water only

• ... water and glass.

• ... any medium.

• ... vacuum or roughly air.

why is x-ray used in medical imaging?

• it can penetrate most soft tissues and organs and even some part of bones with various intensities.

• it can penetrate most tissues and organ and even some part of bones with only one intensity.

• it is invisible.

• it is highly abundant and cheap.