Question 197: AC fundamentals

Question

An AC source rated 220 V, 50 Hz is connected to a resistor. The time taken by the current to change from its maximum to the rms value is :

Accepted Answer

$$I = {I_0}\sin \omega t $$
$$ \Rightarrow $$ $${{{I_M}} \over {\sqrt 2 }} = {I_M}\sin \omega t$$
$$ \Rightarrow $$ $$\omega t = {\pi  \over 4}$$
$$ \Rightarrow $$ $$t = {\pi  \over {4\omega }}$$ $$ = {\pi  \over {4\left( {2\pi f} ight)}}$$
$$ \Rightarrow $$ t = $${1 \over {8 	imes 30}} = {1 \over {400}}$$ = 2.5 ms

Answer

2.5 ms

Answer

25 ms

Answer

2.5 s

Answer

0.25 ms

AC fundamentals

An AC source rated 220 V, 50 Hz is connected to a resistor. The time taken by the current to change from its maximum to the rms value is :

Choose the correct answer: