Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
-The current I, in amperes, flowing through a particular ac (alternating current) circuit at time t seconds is $$I = 220 \sin ( 65 \pi t )$$ What is the period and amplitude of the current?

A) period $= \frac { \pi } { 120 }$ second, amplitude $= 60$
B) period $= \frac { 1 } { 30 }$ second, amplitude $= 120$
C) period $= 60 \pi$ seconds, amplitude $= \frac { 1 } { 30 }$
D) period $= \frac { 1 } { 480 }$ second, amplitude $= 480$