Question

1. in rl series circuits, r and ( x_{l} )

a never oppose current

oppose current at right angles

c oppose current at all angles

d none of the above

Explanation:

In an RL series circuit, resistance \( R \) is in - phase with the current, and inductive reactance \( X_{L} \) leads the current by \( 90^{\circ} \). Using phasor analysis (where voltage across \( R\) \( V_{R}=IR\) is in - phase with current \( I\), and voltage across \( L\) \( V_{L} = IX_{L}\) leads \( I\) by \( 90^{\circ}\)), the impedance \( Z=\sqrt{R^{2}+X_{L}^{2}}\) (similar to a right - angled triangle in the complex plane). So, \( R\) and \( X_{L}\) oppose current at right angles.

Answer:

B. oppose current at right angles