If a magnet is attracted to a metal object what can you say about the pole of the magnet and the pole of a object ?
1 answer:
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Answer:
C. -12 ab
Explanation:
The restoring force on a spring is given by Hooke's law:
where
k is the spring constant
x is the stretched (or compressed) displacement of the spring
In this problem we have:
k = 4a
x = 3b
Substituting into the equation, we find:
And the negative sign means that the direction of the force (negative) is opposite to the direction of the displacement (positive).
The current flowing in silicon bar is 2.02 10^-12 A.
<u>Explanation:</u>
Length of silicon bar, l = 10 μm = 0.001 cm
Free electron density, Ne = 104 cm^3
Hole density, Nh = 1016 cm^3
μn = 1200 cm^2 / V s
μр = 500 cm^2 / V s
The total current flowing in the bar is the sum of the drift current due to the hole and the electrons.
J = Je + Jh
J = n qE μn + p qE μp
where, n and p are electron and hole densities.
J = Eq (n μn + p μp)
we know that E = V / l
So, J = (V / l) q (n μn + p μp)
J = (1.6 10^-19) / 0.001 (104
1200 + 1016
500)
J = 1012480 10^-16 A / m^2.
or
J = 1.01 10^-9 A / m^2
Current, I = JA
A is the area of bar, A = 20 μm = 0.002 cm
I = 1.01 10^-9
0.002 = 2.02
10^-12
So, the current flowing in silicon bar is 2.02 10^-12 A.
Answer:
The appropriate solution is "2.78 mm".
Explanation:
Given:
or,
or,
As we know,
Fringe width is:
⇒
hence,
Separation between second and third bright fringes will be:
⇒
or,