Wilhelm Rontgen invented X-ray machine.

Correct Option: B

Wilhelm Rontgen invented X-ray machine.

MRI stands for magnetic resonance imaging.

Correct Option: C

MRI stands for magnetic resonance imaging.

Laser is a device for producing stimulated radiation. LASER stands for light amplification by stimulated emission of (electromagnetic) radiation.

Correct Option: D

Laser is a device for producing stimulated radiation. LASER stands for light amplification by stimulated emission of (electromagnetic) radiation.

The colour of light is determined by its wavelength. Among seven constituent colours VIBGYOR wavelength of red light is maximum and of violet light is minimum.

Correct Option: B

The colour of light is determined by its wavelength. Among seven constituent colours VIBGYOR wavelength of red light is maximum and of violet light is minimum.

Mirage is an optical illusion. The reason of mirage is total internal reflection of light. In summer air near the ground is hotter and hence rarer than the air above which is responsible for TIR, hence, mirage.

Correct Option: D

Mirage is an optical illusion. The reason of mirage is total internal reflection of light. In summer air near the ground is hotter and hence rarer than the air above which is responsible for TIR, hence, mirage.