Question

A signal generator has an output voltage of 2.0 V with no load. When a 600 Ω load is connected to it, the output drops to 1.0 V. The Thevenin resistance of the generator is

Answer 1

Answer:

600 Ω

Explanation:

when there is no load attached to the generator the circuit is open and zero current flows through the circuit, hence voltage drop across the internal resister is zero.

when 600Ω load is connected current starts flowing through the circuit and  some voltage will drop across the internal resister.

voltage across the load resister is 1 V, so the current through it will be:

I=V/R

I=1/600 A= 1.67mA

voltage drop in the internal resister is:

V= input voltage - output voltage

V=2 V-1 V

⇒V=1 V

Now by using ohm's law

R=V/ I

R=$\frac{1}{1.67*10^{-3} }$    (I= 1.67mA, as the resistors are connected in series)

⇒R=600 Ω

Hence Thevinin resistance of the generator is 600Ω.