The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
Explanation:
(a)
Critical angle is the angle at the angle of refraction is 90°. After the critical angle, no refraction takes place.
Using Snell's law as:
Where,
is the angle of incidence
is the angle of refraction = 90°
is the refractive index of the refraction medium
is the refractive index of the incidence medium
Thus,
The formula for the calculation of critical angle is:
Where,
is the critical angle
(b)
No it cannot occur. It only occur when the light ray bends away from the normal which means that when it travels from denser to rarer medium.
I believe this is known as wave period.
hope this helps!
Archimedes principle states
that
F1 / A1 = F2 / A2
F2 = (A2 / A1) * F1
Also, formula for the force is
F = mg. Formula for the area of the cylinder is A = πr^2, therefore we get
F2 = (πr2^2 / πr1^2) * mg
Since the diameter of the
cylinders are 2 cm and 24 cm, r1 = 12 and r2 = 1.
Substituting the values to the
derived equation, we get
F2 = (π 1^2 / π 12^2) * 2400 * 9.8
F2 = 163.3333 N
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Answer:
Nodes.
Explanation:
Nodes are a point that are on a standing wave that never move.
