Answer:
Explanation: the major difference between an electromagnet and permanent magnet is that the former can have a magnetic field when electric current flows through it and disappears when the flow of the current stops. ... It will always displays the magnetic behaviour.
Edit
In physics, power is the rate of doing work or of transferring heat, i.e. the amount of energy transferred or converted per unit time. Having no direction, it is a scalarquantity. In the International System of Units, the unit of power is the joule per second (J/s), known as the watt in honour of James Watt, the eighteenth-century developer of the condenser steam engine. Another common and traditional measure is horsepower (comparing to the power of a horse). Being the rate of work, the equation for power can be written:
Power
Common symbols
Derivations from
other quantities
P = E/t
P = F·v
P = V·I
P = T·ω
As a physical concept, power requires both a change in the physical system and a specified time in which the change occurs. This is distinct from the concept of work, which is only measured in terms of a net change in the state of the physical system. The same amount of work is done when carrying a load up a flight of stairs whether the person carrying it walks or runs, but more power is needed for running because the work is done in a shorter amount of time.
Answer:
net power is + 2.25 D
Explanation:
Given data
distance vision = -0.25 D
near vision = + 2.50 D
to find out
net power
solution
we have given a person lens power for near is - 0.25 diopter and lens power for near power is +2.50 diopter so
net power is sum of both the power vision
so
net power = distance + near power
put both value we get net power
net power = ( -0.25 D) + ( + 2.50 D)
net power = + 2.25 D
so net power is + 2.25 D
Answer:
Part a)
P = 13.93 kW
Part b)
R = 8357.6 Cents
Explanation:
Part A)
heat required to melt the aluminium is given by
here we have
Since this is the amount of aluminium per hour
so power required to melt is given by
Since the efficiency is 85% so actual power required will be
Part B)
Total energy consumed by the furnace for 30 hours
now the total cost of energy consumption is given as
