Answer: (a) α = 
(b) For r≤R: B(r) = μ_0.
For r≥R: B(r) = μ_0.
Explanation:
(a) The current I enclosed in a straight wire with current density not constant is calculated by:
where:
dA is the cross section.
In this case, a circular cross section of radius R, so it translates as:
For these circunstances, α =
(b) <u>Ampere's</u> <u>Law</u> to calculate magnetic field B is given by:
μ_0.
(i) First, first find for r ≤ R:
Calculating B(r), using Ampere's Law:
μ_0.
.μ_0
B(r) = 
.μ_0
B(r) = 
.μ_0
For r ≤ R, magnetic field is B(r) = .μ_0
(ii) For r ≥ R:
So, as calculated before:
I
Using Ampere:
B.2.π.r = μ_0.I
B(r) = 
.μ_0
For r ≥ R, magnetic field is; B(r) = .μ_0.
For a smooth surface, reflected light rays travel in the same direction. This is called specular reflection. For a rough surface, reflected light rays scatter in all directions. This is called diffuse reflection. Diffuse reflection is when light hits an object and reflects in lots of different directions.
For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters. Notice that gravitational potential energy has the same units as kinetic energy, kg m2 / s2.
Answer:
The process of producing electric energy or the amount of electric energy produced by transforming other forms of energy into electrical energy; commonly expressed in kilowatt-hours (kWh) or megawatt-hours (MWh). Electric power plant efficiency η is defined as the ratio between the useful electricity output from the generating unit, in a specific time, and the energy value of the energy source supplied to the unit in the same time period. For electricity generation based on steam turbines 65% of all prime energy is wasted as heat. The maximum theoretical energy efficiency is defined in more detail by the Rankine cycle. For modern practical systems this is about 40% but less for older generating plant. The efficiency falls still further if fuels with lower energy content such as biomass are used to supply the plant. The economics of power generation based on reciprocating engines depends to a large extent on the use to which the engine is to be put. The cheapest engines available are small petrol-driven engines based on car engines, which are manufactured in large numbers each year.
Explanation:
Work done to lift the rock is 6174 Joule.
To find the answer, we need to know about the work done.
<h3>What's the work done?</h3>
Mathematically, work done = force × distance
<h3>What's the gravitational force acts on the stone here?</h3>
The gravitational force on the stone = mg
= 210× 9.8= 2058N
<h3>What's the work done to lift the stone?</h3>
Work done= 2058× 3
= 6174 Joule
Thus, we can conclude that the work done to lift the stone is 6174 Joule.
Learn more about the work done here:
brainly.com/question/25573309
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