An ideal carnot refrigerator with a performance coefficient (cop) of 2.1 cools items inside of it to 5.0° c. what is the high temperature needed to operate this refrigerator?

a) 7° c
b) 589° c
c) 137° c
d) 16° c

the high temperature needed to operate this refrigerator is C) 137.4° C

Explanation:

Hello!

The carnot refrigeration cycle is one in which a machine absorbs heat from an enclosure and expels it to the surroundings, the equation that defines the COP performance coefficient for this cycle is:

COP=performance coefficient =2.1

T1=  Low temperature

T2=high temperature

Now use algebra to find the high temperature

If we replace the values:

note = remember that the temperature must be in absolute units, for which we must add 273.15 to the low temperature to find the temperature in Kelvin

T1 = 5 + 273.15 = 278.15K

In celsius

T2=410.60-273.15=137.4° C

the high temperature needed to operate this refrigerator is C) 137.4° C

Answer:
you can use reflectors or refractors (lenses) or both. i am a retired optical design engineer, this is what we did, lenses and reflectors for lighting purposes. there are two types of reflectors to absorb light: parabolic and ellipsoid. they have both advantages and disadvantages. most flash lights use reflectors to absorb light into the beam. a lens is relatively expensive so that you can get what you want without them, all the better.