4) For the following pairs of sinusoids, determine which one leads and by how much. a) v(t) = 10 cos(4t – 60°) and i(t) b) v1 (t) = 4 cos(377t + 10°) and v2 (t) = –20 cos 377t c) i(t) = – sin(wt + 30°) and v(t) = 4 sin(4t + 50°) 2 sin(wt + 10°)

What is the frequency of the following sinusoidal voltage signal v(t) = 217 cos (190t + 370 ) V?

Find the period of repetition of the following sinusoidal waveforms and express them in phasor repre- sentation: vi(t) = 12 cos(314t + 10°) V v2(t) = 4 sin(2765t – 75°) V i1(t) = -0.2 sin(600rt – 100°) A i2(t) = -2.5 cos(377nt + 120°) A

Transform each of the following into phasor form: (a) 28 cos (20t) (b) 32 sin (2t-90°) (c) sin (9t+45°) (d) 5 cos 10t+8 cos(10t+45°)