It’s physical something you can physically do
Simple cells have liquid chemicals, making it harder for it to carry. While as dry cells have no liquid chemicals, making it easier to carry.
Answer:
15.32°
Explanation:
We have given the wavelength 
Diffraction grating is 1460 lines per cm
So
(as 1 m=100 cm )
For maximum diffraction
here m is order of diffraction
So 


Raising the temperature results in the radiator giving off photons of high-energy ultraviolet light. As heat is added, the radiator emits photons across a wide range of visible-light frequencies
Light waves travel in straight lines when they are travelling in a uniform medium. This is because the waves are travelling at the same speed.