I think so it ans wold be d.because if the source approaches the observer more and more wavefront will pass and it get squeezed.so wavelength decreases and frequency increases.
To solve this problem it is necessary to apply the definition given in Faraday's law in a solenoid for which it is noted that


Where,
N = Number of loops
A = Cross sectional Area
B = Magnetic Field



Therefore the correct answer is A.
<span>electric, solar, wind, and geothermal.</span>
Answer:
B
Explanation:
The heat from radioactive processes within the planet's interior causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or a tectonic shift.