QUIZ 1 – Sinusoids and Phasors

1. A function that repeats itself after fixed intervals is said to be: ( 2pts)

(a) a phasor (b) harmonic(c) periodic (d) reactive

2. Which of these frequencies has the shorter period? (2pts)

(a) 1 krad/s (b) 1 kHz

3. If v1 = 30 sin(ωt + 100) and v2 = 20 sin(ωt + 500),which of these statements are true? (3pts)

(a) v1 leads v2 (b) v2 leads v1(c) v2 lags v1 (d) v1 lags v2

4. In a linear circuit, the voltage source is (5pts each) vs = 12 sin(103t+ 240) V

(a) What is the angular frequency of the voltage?(b) What is the frequency of the source?(c) Find the period of the voltage.(d) Express vs in cosine form.(e) Determine vs at t = 2.5 ms.

5. Convert i = −10 sin(3t − 850) to cosine form. (8pts)

6. Solve the given complex number and express the result in rectangular form. (10pts)

7. Find a single sinusoid corresponding to the phasor: (10pts)

8. Given i1 (t )=4cos (ωt+30o )∧¿i2 ( t )=5sin (ωt−20 ) , find their sum

1. A function that repeats itself after fixed intervals is said to be: ( 2pts)

(a) a phasor (b) harmonic

(c) periodic (d) reactive

2. Which of these frequencies has the shorter period? (2pts)

(a) 1 krad/s (b) 1 kHz

3. If v1 = 30 sin(ωt + 100) and v2 = 20 sin(ωt + 500),which of these statements are true? (3pts)

(a) v1 leads v2 (b) v2 leads v1(c) v2 lags v1 (d) v1 lags v2

4. In a linear circuit, the voltage source is (5pts each) vs = 12 sin(103t+ 240) V

(a) What is the angular frequency of the voltage?(b) What is the frequency of the source?(c) Find the period of the voltage.(d) Express vs in cosine form.(e) Determine vs at t = 2.5 ms.

5. Convert i = −10 sin(3t − 850) to cosine form. (8pts)

6. Solve the given complex number and express the result in rectangular form. (10pts)

7. Find a single sinusoid corresponding to the phasor: (10pts)

8. Given i1 (t )=4cos (ωt+30o )∧¿i2 ( t )=5sin (ωt−20 ) , find their sum