Difference between impulse and impulsive force

The sun generates both mechanical and electromagnetic waves. which statement about those wave is true?

Which is special about a dc circuit ? a. it has both series and parallel components b. it has only series or only parallel components c. charge moves in a single direction d. charge moves back and forth quickly

If angle "a" is 25°, angle "b" is: a) equal to angle c b) less than angle c c) greater than angle c