Chapter 21, Problem 19P

To determine

The output at a rotation speed of 2500 rpm.

Answer to Problem 19P

Solution:

The output voltage at 2500 rpm is 29 V.

Explanation of Solution

Given info:

Rotation speed of generator of car be ${\omega }_1=\text{1100 rpm}$

Output Rotation speed of generator of car be ${\omega }_2=\text{2500 rpm}$

Applied Emf (voltage)${\text{E}}_1=\text{12}\text{.7 V}$

Formula to be used:

According to the equation $\left(\text{E}\propto \omega \right)$, induced voltage is directly proportional to angular speed.

$\frac{E_1}{{\omega }_1}=\frac{E_2}{{\omega }_2}$

$E_2={\omega }_2\frac{E_1}{{\omega }_1}$

Calculation:

Applying values,

$E_2=\left(12.7\right)\frac{2500}{1100}$

$E_2=\text{28}\text{.86 V}$

$\text{ =29 V }\left(\text{Approximately}\right)$