Question

Quiz-1 Review Questions:  AC Circuits CETT-1405
1: Calculate the frequency “F” for each of the following values of sine wave period.
T = 0.1 sec,      F =
T = 4 milli seconds,    F =                                 
2: A sine wave has a peak of 120V. Determine the Vrms value:
3: A hair dryer having 8 Ohms resistance was connected to 110 Vrms supply. Calculate the following:
Irms =                               Ipeak =                                     
Voltage across the resistor =
Power Lost as heat at the resistor =
4: Convert 0.01 microfarad to picofarad
5: Convert 250 picofarad to microfarad
6: What is the value of a ceramic capacitor if 240 is written on it
7: What is the value of a ceramic capacitor if 0.001 is written on it
8: Two 40 pF capacitors are connected in parallel. Determine the total capacitance
9: Two 40 pF capacitors are connected in series. Determine the total capacitance
10: For RC in series where R = 4.7 Kilo Ohm and C = 0.02 microfarads:
A: Determine the time constant Tau Ƭ
B: Determine how long it takes the capacitor to reach full charge
16: Change 4.2 radians to

Answer 1

Answers:

Answer 1: The term Time Period(T) for a wave corresponds to the amount of time a wave takes to vibrate one full cycle. The term Frequency(F) means, how many cycles of oscillations are produced per second, for a wave.

Relation between Time period and Frequency is,

Here in this question, when T = 0.1 sec,

Similarly, when T = 4 milli second = 4 ms,

Answer 2:

Peak Value is the maximum value achieved by an alternating quantity(alternating current or voltage) during one cycle. It is actually the maximum value or the crest value.

RMS Value(Effective Value) is defined as the square root of means of squares of the instantaneous values of alternating current or voltage. It is actually equals to the steady state current that when flows through a circuit element(resistor) which produces some quantity of heat which is equal to the heat produced by the alternating current when flows through the same circuit element(resistor)

Relation between RMS and Peak Value is,

From given question, when Peak value = 120V, then

Answer 3:

Already described about RMS value of alternating quantities(Current and Voltage) in above answer. Relation between Irms and Vrms is,

where Z is the total impedance of the circuit. Here in this question the circuit is purely Resistive circuit(with R = 8 ohm) and hence

Voltage across the resistor(when it is in AC circuit) is the RMS value of Voltage which is Vrms and hence the voltage across the given resistor is equal to

Power loss as heat at the resistor for a resistive circuit is given by the equation,

Hence in this question the power lost as heat is,

Answer 4:

Here in this question it asks to convert 0.01 microfarad to picofarad. Microfard, picofarad, nanofarad, etc.. are the units of  Capacitance of a Capacitor. Capacitance is the ability of a capacitor to store electric charge in it. Unit of Capacitance is Farad.

micro, nano and pico are the suffixes which corresponds to , and respectively.

Question is to convert 0.01 microfard to picofard

0.01 microfarad = 10000 picofarad

Answer 5:

Question is to convert 250 picofarad to microfarad.

As said above in answer to the 4th question part, here also we can use the prefix values for the conversion.

250 picofarad = 0.00025 microfarad