Coefficient of performance is A) 1 - Qcold/Qhot. B) Q/m. C) ...

[Bob-Dole]

Coefficient of performance is
 
  A) 1 - Qcold/Qhot.
  B) Q/m.
  C) Qout/Win.
  D) Q - W.
  E) 1 - Tcold/Thot.

Question 2

Usually one can touch the terminals of a battery (e.g., 1.5 volts) with no dire consequences.
 
  Why do hospital intensive care rooms go to great effort and expense to attach ground wires to equipment in order to guard against the presence of low potentials? (i.e., why are low voltages hazardous in hospitals?)

[gasdhashg]

Answer to Question 1

C

Answer to Question 2

Most of the body resistance is at the relatively dry skin-air boundary and this is sufficient to prevent dangerous currents through the body. In a hospital setting one may have needles or other probes penetrating this protective layer and the possibility exists for much larger currents being driven by relatively small voltages.

[Bob-Dole]

Thanks

[gasdhashg]

Welcome