ABSTRACT
Every circuit suffers from at least one form of time delay which usually occurs between its input and output whenever signals are applied to it. This delay is known as Time Constant of the circuit which is usually define to be the response time of the circuit whenever a step voltage is applied initially to it. The unit of this response time is Tau, usually abbreviated asT. It is worthy to note that that in any circuit or system the resultant time constant is mainly dependent on the reactive component.
Also, time constant, T, is the time taken for the charging or the discharging of a capacitor’s energy relative to a certain percentage of its maximum supply.
Whenever a resistor is connected in series with a capacitor an RC circuit is formed. In an RC circuit, the capacitor gets charged gradually via the resistor until the voltage across it is the same as that of the supply voltage. Here the time constant is usually referred to as the transient response time, T, which is equal to R xC, where R is the value of the resistance of the resistor in Ohms and C is the value of the capacitance of the capacitor. These are the bases of every RC circuit.
Answer To Question 1
An increase in the size of the capacitor will have a greater impact upon the time constant due to the fact that in any circuit or system the resultant time constant is mainly dependent on the reactive component. In this practical exercise, the reactive component is capacitance.
Calculations
Time constant= RC
When R=1kΩ, C=0.01µF
Percentage difference= (100-96)/100 = 4%
Time constant= 1E3 x0.01E-6 = 100 µs
When R=500Ω, C=0.01µF
Time constant= 500 x0.01= 50 µs
Percentage difference= (50-48)/50 = (2/50) x 100 = 4%
Reference
Wayne. Storr. Electronics Tutorial about the RC Time Constant . Basic Electronics Tutorials.
10. Nov. 2013. Web. 11 Nov. <http://www.electronics-tutorials.ws/rc/rc_1.html>
