This is the order of the spectrum from highest frequency to lowest frequency:
Gamma Ray (Highest energy em wave)
X Ray (Used in medical imaging)
Ultra violet (dangerous to human skin)
visible light (human eye can see)
Infrared (medium frequency)
Microwave (used to heat food)
Radio (longest wavelength)
The correct answer is a) 10 Pa.
In fact, the pressure exerted on some point of a fluid is transmitted with equal intensity to every point of the fluid (Pascal's law).
In this case, therefore, the pressure exerted by piston 1 on the fluid (10 Pa) is transmitted through the fluid to piston 2, with same intensity, 10 Pa.