Self Test


  1. An ac supply with a peak current of 5.0 A passes through a 10 W resistor. Calculate:


a)      the rms current                                                                                              

b)      the rms pd across the resistor                                                                        

c)      the peak power                                                                                              

d)     the mean power supplied                                                                              


  1. The r.m.s. value of an alternating voltage is 12 V.  What is the peak voltage?         


  1. In AC waveform is shown in the graph below:

    1. What is the time period?                                                                                
    2. What is the frequency?                                                                                  
    3. What is the peak value?                                                                                 
    4. What is the r.m.s. value?                                                                                


  1. 3.0 MW of power is transmitted at a potential difference of 100 kV along cables of total resistance 5.0 W.  Calculate:
    1. The current in the cables;                                                                               
    2. The power wasted in the cables.