Question 189: AC fundamentals

Question

A 0.07 H inductor and a 12$$\Omega$$ resistor are connected in series to a 220V, 50 Hz ac source. The approximate current in the circuit and the phase angle between current and source voltage are respectively. [Take $$\pi$$ as $${{22} \over 7}$$]

Accepted Answer

$$\phi  = {	an ^{ - 1}}\left( {{{{X_L}} \over R}} ight)$$
$${X_L} = \omega L$$
$${X_L} = 2 	imes {{22} \over 7} 	imes 50 	imes 0.07 = 22\Omega $$
$$\phi  = {	an ^{ - 1}}\left( {{{22} \over {12}}} ight)$$
$$R = 12\Omega $$
$$\phi  = {	an ^{ - 1}}\left( {{{11} \over 6}} ight)$$
$$Z = \sqrt {X_L^2 + {R^2}}  = 25.059$$
$$I = {V \over Z} = {{220} \over {25.059}} = 8.77A$$

Answer

8.8 A and $${	an ^{ - 1}}\left( {{{11} \over 6}} ight)$$

Answer

88 A and $${	an ^{ - 1}}\left( {{{11} \over 6}} ight)$$

Answer

0.88 A and $${	an ^{ - 1}}\left( {{{11} \over 6}} ight)$$

Answer

8.8 A and $${	an ^{ - 1}}\left( {{{6} \over 11}} ight)$$

AC fundamentals

A 0.07 H inductor and a 12$\Omega resistor are connected in series to a 220V, 50 Hz ac source. The approximate current in the circuit and the phase angle between current and source voltage are respectively. [Take \pi as {{22} \over 7}$]

Choose the correct answer: