The output specs show that it will provide a DC voltage of 7

The output specs show that it will provide a DC voltage of 7.5V and a current of 1A (specs for these always show a maximum possible current that can be drawn the device). Assuming that the maximum current is being drawn by the wifi router, what is the power being delivered to the router? Since 16W is being consumed by this power adapter but it is delivering much less power to the router, where does the remaining power go? If you could touch this supply while it operating what would that tell you about where some of the power goes?

Solution

a)

power delivered to rotor = 7.5*1=7.5 W

b)

The remaining power appears as loss and dissipated as heat energy. When we touch this while operation we get a tiny shock.