# Thread: Linear function Word Problem

1. ## Linear function Word Problem

It has been found through the series of experiments that voltage V at the semiconductor diode is related to the charge Q at the diode by the formula V(Q) = V0 (100.434Q/Q0 – 1),
where
Q0 and V0 are some constant reference values measured in Coulombs and Volts, correspondingly.

Find the ratio of V/V0 when the charge Q is 10% grater than Q0. Round off your answer to one decimal place.
Which charge (in Coulombs) on the diode is when the voltage is 0 Volts? Present your answer with one decimal palce.

Assuming that V0 = 0.001 V, find what is the voltage in the diod when its charge is 10 times greater than the reference charge Q0. Round off your answer to three decimal places.

2. ## Re: Linear function Word Problem

Can someone please show me how to work this problem out. I am confused by the Qo/Q and Vo/V. How do they relate to each other?

3. ## Re: Linear function Word Problem

I think your subscript is supposed to be a subscript: Is it
$\displaystyle V= V_0 (10^{0.434\frac{Q_0}{Q}}- 1)$
or
$\displaystyle V= V_0 10^{0.434\frac{Q_0}{Q}- 1}$

In either case, start by dividing both sides by $\displaystyle V_0$ so the left side is $\displaystyle \frac{V}{V_0}$. If "Q is 10% greater than $\displaystyle Q_0$", then $\displaystyle Q= 1.1Q_0$ so that $\displaystyle \frac{Q}{Q_0}= 1.1$ and $\displaystyle \frac{Q_0}{Q}= \frac{1}{1.1}= 0.9091$, approximately. Put that into the right side of the equation and do the calculations.