The percent efficiency of the given PV cell is to be calculated. Concept Introduction: The percent of the input power that is converted into the output power by a PV cell is called its efficiency. Percent efficiency of a PV cell is 100 multiplied by the ratio of power out and power in. Percent efficiency = Power out Power in × 100 % ...... (1)

Question

In Table 7.2 (Energy Expenditure of a 180-Pound Person During Selected Exercises)Links to an external site. in the course textbook, it is claimed that a person climbing stairs expends about 1200 kcal/hr. The maximum human power output for short-term effort is approximately 1200 W (remember 1 W = 1 J/s). Is the value of 1200 kcal/hr a reasonable estimate of average power output by a person climbing stairs? Note: Power is defined as energy per time, so 1200 kcal/hr has units of energy per time. A watt is the SI unit of power and has units of J/s. So to approach this problem you will need to convert one power measurement into the other. Group of answer choices It comes out to be 1400 W, which is too high It is impossible to convert kcals into joules since one is an SI unit and the other isn't It comes out to be 1.395 x 103 W, so the value in the table seems reasonable It comes out to be 960 W, that is too high It comes out to be 1.4 W and that is too low

Answer 1

Question

Chapter 10, Problem 27E

Interpretation Introduction

Interpretation:

The percent efficiency of the given PV cell is to be calculated.

Concept Introduction:

The percent of the input power that is converted into the output power by a PV cell is called its efficiency.

Percent efficiency of a PV cell is 100 multiplied by the ratio of power out and power in.

Percent efficiency=Power outPower in×100% ...... (1)

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