Question

Eels are able to generate current with biological cells called electroplaques. The electroplaques in an eel are arranged in 100 rows, each row stretching horizontally along the body of the fish containing 5000 electroplaques. The arrangement is suggestively shown below. Each electroplaques has an emf of 0.15 V and internal resistance of 0.25$\Omega$. The water surrounding the eel completes a circuit between the head and its tail. If the water surrounding it has a resistance of 500 ohm, the current an eel can produce in water is about

• A. 1.5 A
• B. 3.0 A
• C. 15 A
• D. 30 A

Answer 1

The correct option is A 1.5 A

Given problem is the case of mixed grouping of cells

So total current produced $i=\frac{nE}{R+\frac{nr}{m}}$
Here m = 100, n = 5000, R = 500$\Omega$
E = 0.15V and r = 0.25$\Omega$

$\Rightarrow i=\frac{5000\times 0.15}{500+\frac{5000\times 0.25}{100}}=\frac{750}{512.5}\approx 1.5A$