(a) the three resistors are in parallel, so the equivalent resistance R is given by
1/R= 1/5 + 1/10 +1/15
1/R= 11/30
R=2.7ohm
(b) Voltage in the circuit= 120 V
(c) for current, we use ohm's law
V= i R
120= i (2.7)
i=44 A
Answer:
i think B. Deviated septum
Answer:
Free-fall is defined as the movement where the only force acting on an object is the gravitational force.
By the second Newton's law, we have that:
F = m*a
Where F = Force, m = mass, a = acceleration.
We can write this as:
a = F/m
And the gravitational force can be written as:
F = (G*M/r^2)*m
Where G is the gravitational constant, M is the mass of the Earth in this case, and r is the distance between both objects (the center of the Earth and the free-falling object)
As the radius of the Earth is really big, the term inside the parentheses is almost constant in the region of interest, then we can write:
G*M/r^2 ≈ g
And the gravitational force is:
F = g*m
And by the second Newton's law we had:
a = F/m = (g*m)/m = g
a = g
Then the acceleration does not depend on the mass of the object.
Then the thing that is common among the free-falling objects is the vertical acceleration.
Answer:
a) 222/cm^3
b) The Ec with respect to Ef and Ev = -0.107ev
c) Resistance, R = 467 ohms
Explanation:
(a) From the velocity and the applied electric field, we can calculate the mobility of holes:
υdp = µpε, µp = υdp/ε = 2×10^5/1000
= 200cm2/V.s
From a), we find Nd is equal to 4.5×1017/cm3
. Hence,
n = Nd = 4.5×10^17/cm3
, and p = ni^2/n
= ni^2/Nd
= 10^20 / 4.5×10^17 = 222/cm3
.
Clearly, the minority carrier is hole.
(b) The Fermi level with respect to Ec is
Ef = Ec - kTln(Nd/Nc) = Ec - 0.107 eV.
(c) R = ρL/A. Using Equation, we first calculate the resistivity of the sample:
σ = q(µn n + µp p) ≈ qµn n = 1.6×10^-19 × 400 × 4.5×10^17 = 28.8/Ω-cm, and
ρ= σ
-1 = 0.035 Ω-cm.
Therefore, R = (0.035) × 20µm / (10µm× 1.5µm) = 467 Ω.
We don't know the change in velocity, so can't answer.
