Answer:
Longitudinal and mechanical waves require a medium to support their transmission:
C) is the correct answer
Electric and magnetic field vectors are perpindicalar to each other in a electromagnetic wave. Passing stay current through a straight conductor shows some magnetic flux.
Answer : 2446 years.
Explanation :
Length of semi major axis is, 
According to Kepler's third law, square of time period of an orbit is directly proportional to the cube of the semi major axis.
i.e 
where G is gravitational constant
M is mass of sun, 
So, 




since, 
So, orbital period is approximately 2446 years.