Question

A 100-watt light bulb illuminates a solar cell. The electricity from the solar cell operates a water pump that delivers 1 watt of power. What is the efficiency of the system?

Answer 1

The efficiency of the system where a 100-watt light bulb illuminates a solar cell, which powers a water pump with a 1 watt output, is 1%.

Step-by-step explanation:

The efficiency of the system is calculated by comparing the output power to the input power. In this case, if a 100-watt light bulb illuminates a solar cell and the electricity from the solar cell operates a water pump that delivers 1 watt of power, the efficiency (η) of the system can be found using the formula: η = (output power / input power) × 100%. Therefore, the efficiency of this system is (η = (1 W / 100 W) × 100%) which equals 1% efficiency. This is a simple calculation that demonstrates a common issue with energy conversion systems, where a lot of energy is often lost in the process of converting one form of energy to another, resulting in low conversion efficiency.

Answer 2

1 %

Step-by-step explanation:

The efficiency of a system is defined as the ratio between the energy produced and the energy in input:

`\eta = (E_(out))/(E_(in))\cdot 100`

The same formula can also be rewritten in terms of the power produced and the power in input:

`\eta = (P_(out))/(P_(in))\cdot 100`

Since in this problem we have:

`P_(in)=100 W\\P_(out)=1 W`

The efficiency is

`\eta = (1 W)/(100 W)\cdot 100`=1 \%