Question

If reinforcement is required whenever the potential drops to 20% or less of the $V_0$ how soon (after how many axons) is it required?

• A. 4.11
• B. 41.1
• C. 411
• D. none of these

Answer 1

The correct option is C 411

$R=6.4k\Omega ,R^{\prime }=800000k\Omega$

$R_{AB}=R+\sqrt{R^2+2R^{\prime }R}\bigsqcup 32\times {10}^5\Omega$
$=\frac{2R(R^{\prime }+R_{AB})}{R^{\prime }{R}_{AB}}+1$
$=\frac{12.8\times {10}^3\times 8\times {10}^8}{8\times {10}^8\times 32\times {10}^5}+1=1.004$
$.2V_0=\frac{V_0}{(1.004{)}^n}$ or $n=411$