Question 41: AC fundamentals

Question

$220 \mathrm{~V}$ ac is more dangerous than $220 \mathrm{~V}$ dc Why?

Accepted Answer

The impedance of an inductor ($Z_L$) is given by the formula:
$Z_L = 2 \pi fL$
where:
$f$ is the frequency of the AC source in Hertz (Hz),
$L$ is the inductance in Henrys (H),
$2\pi f$ represents the angular frequency of the AC source.
In this case, we are dealing with a maximum current ($I_{	ext{max}}$) of $\sqrt{2}$ A and a voltage source of $200 \, V$ operating at $50 \, Hz$. The relationship between the voltage ($V$), impedance ($Z_L$), and maximum current ($I_{	ext{max}}$) can be expressed as:
$V = I_{	ext{max}} \cdot Z_L$
We can rearrange this formula to solve for $L$:
$L = \frac{V}{I_{	ext{max}} \cdot 2 \pi f}$
Substituting the given values:
$L = \frac{200}{\sqrt{2} \cdot 2 \pi \cdot 50}$
After simplification:
$L = \frac{200}{\sqrt{2} \cdot 314.16}$
$L = \frac{200}{222.53}$
Further simplification gives:
$L = \frac{2}{\sqrt{2} \pi}$
Simplifying the $\sqrt{2}$ in the denominator by multiplying numerator and denominator by $\sqrt{2}$ gives:
$L = \frac{2\sqrt{2}}{\pi \sqrt{2}}$
$L = \frac{2}{\pi} \, H$
Hence, the correct answer is Option C: $\frac{2}{\pi} \, H$.

Answer

The peak value of ac is greater than the given value of dc

Answer

Shock received from ac is always repulsive

Answer

The frequency of ac is more than that of dc

Answer

The speed of ac is more than that of $\mathrm{dc}$

AC fundamentals

220 \mathrm{~V}$ ac is more dangerous than $220 \mathrm{~V}$ dc Why?

Choose the correct answer: