Question

Electric eels generate electric pulses along their skin that can be used to stun an enemy when they come into contact with it. Tests have shown that these pulses can be up to $\mathbf{500}\mathbf{V}$ and produce currents of $\mathbf{80}\mathbf{mA}$(or even larger). A typical pulse lasts for $\mathbf{10}\mathbf{ms}$. What power and how much energy are delivered to the unfortunate enemy with a single pulse, assuming a steady current?

Short answer

The power and energy delivered to the enemy is 40 W and 0.40 J respectively.

Step-by-step solution

Concept/Significance of steady current.

The term "steady current" refers to a current that does not fluctuate over time. Any stimulus generally responds with a transient, pulsing current that settles with time and has a steady-state current value.

Determination of power and energy delivered to the enemy with a single pulse

The power is given by,

P = V . l

Here, V is the maximum potential/pulse and I is the current given.

Substitute all the values in the above,

P= ( 500 V ) ( 80 mA )

=40 W

The energy delivered is given by,

E = Pt

Here, P is the power transferred to the enemy and t is the time.

Substitute all the values in the above,

$$\begin{gathered} E=(40\mathrm{W})(10\times {10}^{-3}\mathrm{s}) \\ =0.40\mathrm{J} \end{gathered}$$

Thus, the power and energy delivered to the enemy is 40 W and 0.40 J respectively.