Answer:
162.8 K
Explanation:
initial current = io
final current, i = io/8
Let the potential difference is V.
coefficient of resistivity, α = 43 x 10^-3 /K
Let the resistance is R and the final resistance is Ro.
The resistance varies with temperature
R = Ro ( 1 + α ΔT)
V/i = V/io (1 + α ΔT )
8 = 1 + 43 x 10^-3 x ΔT
7 = 43 x 10^-3 x ΔT
ΔT = 162.8 K
Thus, the rise in temperature is 162.8 K.
Answer:
(a) ε = 1373.8.
(b) The wingtip which is at higher potential.
Explanation:
(a) Finding the potential difference between the airplane wingtips.
Given the parameters
wingspan of the plane is = 18.0m
speed of the plane in north direction is = 70.0m/s
magnetic field of the earth is = 1.20μT
The potential difference is given as:
ε = Blv
where ε = potential difference of wingtips
B = magnetic field of earth
l = wingspan of airplane
v = speed of airplane
ε = 1.2 x 18.0 x 63.6
ε = 1373.8
(b) Which wingtip is at higher potential?
The wingtip which is at higher potential.
Complete Question:
A hollow cylinder with an inner radius of 4.0mm and an outer radius of 30mm conducts a 3.0-A current flowing parallel to the axis of the cylinder. If the current density is uniform throughout the wire, what is the magnitude of the magnetic field at a point 12mm from its center?
Answer:
The magnitude of the magnetic field = 7.24 μT
Explanation:
Inner radius, a = 4.0 mm = 0.004 m
Outer radius, b = 30 mm = 0.03 m
Radius, r = 12 mm = 0.012 m
let h² = b² - a²
h² = 0.03² - 0.004²
h² = 0.000884
Let d² = r² - a²
d² = 0.012² - 0.004²
d² = 0.000128
Current I = 3A
μ = 4π * 10⁻⁷
The magnitude of the magnetic field is given by:
B = 7.24 * 10⁻⁶T
B = 7.24 μT
