Answer:
The magnetic field is 
Explanation:
From the question we are told that
The inner radius is 
The outer radius is 
The distance from the axis of the conductor is 
The current carried by the conductor is 
According to Ampere's circuital law , the magnetic field at a point that is
from the axis of the conductor
![B = \frac{\mu_oI}{2 \pi d } [\frac{d - r_1}{r_2 -r_1} ]](https://tex.z-dn.net/?f=B%20%3D%20%20%5Cfrac%7B%5Cmu_oI%7D%7B2%20%5Cpi%20d%20%7D%20%5B%5Cfrac%7Bd%20-%20r_1%7D%7Br_2%20-r_1%7D%20%5D)
Where
is the permeability of free space with a value of
substituting values
![B = \frac{(4 \pi *10^{-7})(80)}{2 * 3.142 * 2 *10^{=3} } [\frac{(2^2 - 1 ^2 )*10^{-3}}{(3^2 - 1^2) *10^{-3}} ]](https://tex.z-dn.net/?f=B%20%3D%20%20%5Cfrac%7B%284%20%5Cpi%20%2A10%5E%7B-7%7D%29%2880%29%7D%7B2%20%2A%203.142%20%2A%202%20%2A10%5E%7B%3D3%7D%20%7D%20%5B%5Cfrac%7B%282%5E2%20-%201%20%5E2%20%29%2A10%5E%7B-3%7D%7D%7B%283%5E2%20-%201%5E2%29%20%2A10%5E%7B-3%7D%7D%20%5D)

Answer: the sun
Explanation:
The sun's radiant energy reaches the earth's surface either directly through radiation, indirectly through convection, or it can move "across" or "through" objects or materials on the surface via conduction. Let's look more closely at each case. We've probably experienced the feeling of "warmth" of the sun on our skin on a sunny day. Light energy from the sun is reaching us across space and down through the atmosphere through radiation. A dark colored vehicle in the sun quickly becomes warm (or hot!) to the touch because of radiation. The light energy from the sun heats the air in the earth's atmosphere, and this drives convection and transfers thermal energy around. It is possible that we've felt a "hot breeze" on our skin on sunny days. The thermal energy in the air will be carried to objects in its path, and it will warm them.
Answer:
α = 1.114 × 10⁻³ (°C)⁻¹
Explanation:
Given that:
Length of rod (L) = 1.5 m,
Diameter (d) = 0.55 cm,
Area (A) = 
Radius (r) = d / 2 = 0.275 cm,
Voltage across the rod (V) = 15.0 V.
At initial temperature (T₀) = 20°C, the current (I₀) = 18.8 A while at a temperature (T) = 92⁰C, the current (I) = 17.4 A
a) The resistance of the rod (R) is given as:

Therefore the resistivity and for the material of the rod at 20 °C (ρ) is:
b) The temperature coefficient of resistivity at 20°C for the material of the rod (α) can be gotten from the equation:
![R_T=R_0[1-\alpha (T-T_0)]\\but,R_T=\frac{V}{I}=\frac{15}{17.4}=0.862\\](https://tex.z-dn.net/?f=R_T%3DR_0%5B1-%5Calpha%20%28T-T_0%29%5D%5C%5Cbut%2CR_T%3D%5Cfrac%7BV%7D%7BI%7D%3D%5Cfrac%7B15%7D%7B17.4%7D%3D0.862%5C%5C)
Rearranging to make α the subject of formula:

Answer:
The following is the relation between electric force and field

Explanation:
Electric force is the magnitude of electrostatic forces between two charges which is directly proportional to product of both charges and inversely proportional to the square of the distance between them.

Here k is the coulumb's constant.
Where as the electric field is the electric force per unit charge. It is the function of electric force. It is the vector quantity and its direction is taken radially inward or outward depending on the nature of charge.
Its equation is
Electric Field 
Electric Field units are in volts where as Electric force units are newtons.