One of the similarities between electric and magnetic fields is that they both
always form closed loops.
A. True
B. False

FALSE

Explanation:

Electric fields are produced by two kinds of charges, positive and negative. Magnetic fields are associated with two magnetic poles, north and south, although they are also produced by moving charges. Like poles repel and unlike poles attract.

Electric lines of force due to two positive charges start from either charge and end at infinity. In all cases we see that electric lines of force , either from infinity or from a positive charge never come back to the same point, because the field lines starts (or diverges) from the positive charge and terminate (or converges) on negative charge. If the electric field lines form closed loop, these line must originate and terminate on the same charge which is not possible because  electric field lines always moves from positive to negative and hence they don't form closed loops.

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.