Crystalgazay48
Answered

Question:
If a machine is supplied with power at a rate of [tex]$4,000 \, \text{W}$[/tex], and it does useful work with a power of [tex]$1,900 \, \text{W}$[/tex], what is the efficiency of the machine?

Answer Options:
Select one:

A. Efficiency [tex]= 80 \%[/tex]

B. Efficiency [tex]= 47.5 \%[/tex]

C. Efficiency [tex]= 195 \%[/tex]

D. Efficiency [tex]= 2.1 \%[/tex]



Answer :

GinnyAnswer
To determine the efficiency of the machine, we use the formula for efficiency which is given by:

[tex]\[ \text{Efficiency} = \left( \frac{\text{Useful Power Output}}{\text{Power Input}} \right) \times 100 \][/tex]

Given:
- Power Input (Power Supplied) = [tex]\( 4000 \text{ W} \)[/tex]
- Useful Power Output (Power Useful) = [tex]\( 1900 \text{ W} \)[/tex]

Substituting the values into the formula:

[tex]\[ \text{Efficiency} = \left( \frac{1900 \text{ W}}{4000 \text{ W}} \right) \times 100 \][/tex]

[tex]\[ \text{Efficiency} = \left( \frac{1900}{4000} \right) \times 100 \][/tex]

[tex]\[ \text{Efficiency} = 0.475 \times 100 \][/tex]

[tex]\[ \text{Efficiency} = 47.5 \% \][/tex]

Therefore, the efficiency of the machine is [tex]\( 47.5 \% \)[/tex].

The correct answer is:
Efficiency [tex]$=47.5 \%$[/tex]