The amplitude, or magnitude, of a sinusoidal source is the maximum value of the source. What is the amplitude of the voltage source described as v(t)=50cos(2000t−45∘) mVv(t)=50cos⁡(2000t−45∘) mV ?

A = 0.05 V

Explanation:

Sinusoidal Functions

A sinusoid or sinusoidal function is a sine or cosine which general equation is

Or also

Where A is the amplitude or maximum value, w is the angular frequency, t is the time and is the phase shift.

Comparing the given expression with the general formula

We can establish that A=50 mV = 0.05 V

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27