which ems wave has a wavelength equal to the size of a needle point and is used in heat lamps for reptiles…

Brief Explanations:

Infrared waves have wavelengths in the range that can be comparable to the size of a needle point. They are used in heat lamps for reptiles (as they emit heat which is in the infrared range) and in night - vision technology (as objects emit infrared radiation which can be detected even in low - light conditions). Radio waves have much longer wavelengths, visible light has wavelengths in the range that we can see (not typically used in the described applications in the same way), and microwaves have wavelengths that are larger than what is described for the needle - point size in this context.

Answer:

Infrared