Answer:
<em>"the magnitude of the magnetic field at a point of distance a around a wire, carrying a constant current I, is inversely proportional to the distance a of the wire from that point"</em>
Explanation:
The magnitude of the magnetic field from a long straight wire (A approximately a finite length of wire at least for close points around the wire.) decreases with distance from the wire. It does not follow the inverse square rule as is the electric field from a point charge. We can then say that<em> "the magnitude of the magnetic field at a point of distance a around a wire, carrying a constant current I, is inversely proportional to the distance a of the wire from that point"</em>
From the Biot-Savart rule,
B = μI/2πR
where B is the magnitude of the magnetic field
I is the current through the wire
μ is the permeability of free space or vacuum
R is the distance between the point and the wire, in this case is = a
Complete Question
The complete question is shown on the first uploaded image
Answer:
a
b
Explanation:
From the question we are told that
The image distance is 
The value of the image is negative because it is on the same side with the corrective glasses
The object distance is 
The reason object distance is because the object father than it being picture by the eye
General focal length is mathematically represented as
substituting values
=>
Generally the power of the corrective lens is mathematically represented as
substituting values
I think it’s output because output work is work done by a machine
Answer:
0.232 mm.
Explanation:
Power, P = 96 W
Voltage, V = 120 V
Length of wire, l = 4.2 m
Let r be the radius of the wire.
Resistivity of nichrome, ρ = 1.5 x 10^-6 ohm metre
P = V^2 / R
R = 120 x 120 / 96 = 150 ohm
r = 1.16 x 10^-4 m
Diameter = 2 x r = 2 x 1.16 x 10^-4 = 2.32 x 10^-4 m = 0.232 mm
Thus, the diameter of the wire is 0.232 mm.
Answer:
21.85 C
Explanation:
mass of iron = 1.5 kg, initial temperature of iron, T1 = 500 C
mass of water = 20 kg, initial temperature of water, T2 = 18 C
let T be the equilibrium temperature.
Specific heat of iron = 449 J/kg C
specific heat of water = 4186 J/kg C
Use the principle of caloriemetry
heat lost by the hot body = heat gained by the cold body
mass of iron x specific heat of iron x decrease in temperature = mass of water x specific heat of water x increase in temperature
1.5 x 449 x (500 - T) = 20 x 4186 x (T - 18)
336750 - 673.5 T = 83720 T - 1506960
1843710 = 84393.5 T
T = 21.85 C
