What force is responsible for the repulsion between two positively charged particles?

Electromagnetic force

Explanation:

When two stationary charges are placed at some distance from each other then the force of attraction or repulsion between then is given by the equation

here we know that

= two charges

r = distance between two charges

now we know that the two charges are repelling each other then they must be of same type and if two charges are attracting each other then it must be of opposite nature.

So here force between the two charges are electrostatic force

the answer is a)

mark brainliest

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.