Complete question is;
Does the galvanometer deflect to the left or the right when
a) the magnet is being pushed in
b) the magnet is being pulled out
c) the magnet is being held steady?
Answer:
Option A - when the magnet is being pulled out
Explanation:
Faraday’s law of electromagnetic induction states that: “Voltage is induced in a circuit whenever relative motion exists between the conductor and the magnetic field, and the magnitude of the voltage will be proportional to the rate of change of the flux”.
Now, applying it to the question, When the magnet is moved towards the sensitive center of the galvanometer and then pulled out, the needle of the galvanometer will deflect away from its center position in one direction only but when it is held steady, the needle of the galvanometer will return back to zero.
When two or more waves combine to produce a new wave, that's 'interference'.
-- If the new wave has larger displacements (amplitude), then it's <em>CON</em>structive interference.
-- If the new wave has smaller displacements (amplitude), then it's DEstructive interference.
The only thing we know of so far that can shift light to longer wavelengths is the "Doppler" effect. If the source and the observer are moving apart, then the observer sees wavelengths that are longer than they should be. If the source and the observer are moving toward each other, then the observer sees wavelengths that are shorter than they should be. It works for ANY wave ... sound, light, water etc. The trick is to know what the wavelength SHOULD be. If you know that, then you can tell whether you and the source are moving together or apart, and you can even tell how fast. If the lines in a star"s spectrum are at wavelengths that are too long, then from everything we know right now, the star and Earth are moving apart.