IE1206 Home Problem 4 Solved

Problem 1

Per-Erik connected a load resistor RL to a battery rated to be 9V. He measured the voltage (VL) over the load resistor for different values of RL. The measured data is shown in the table below.  

RL
100 k
10 k
1 k
177 
38 
VL
9.16
9.15
9.01
8.58
7.28
 

Determine the Thevenin equivalent of the 9V battery. 
Problem 2

 

A) Determine the output voltage Vout as as function of V1,V2, R1, R2, R3, R4 and R5.

Assume the operational amplifiers are ideal and operates in the linear region.  B) Determine Vout if V1=2 V, V2=3 V and R1=R2=R3=R4=R5=2 k.  
Problem 3 

 

(A)  Determine the output voltage Vout assuming that the op-amp operates in the linear region and is ideal.

(B)  What is the function of the op-amp (think about the op-amp input resistance)? What function does the circuit perform?

 
 

 

 

Problem 4

 

The switch has been open for a long time. At time t=0 s the switch closes.

Determine the voltage over the capacitor VC at time t=2 ms. VA=6 V, R1=R2=10 k, R3=5 k and C=100 nF.
Problem 5

 

The switch has been closed for a long time. At t=0 s the switch opens.  VA=5 V, R1=1 k, R2=4 k and C=2.5 nF.

A)    What is the enegry stored in the capacitor at t=0 s?  

B)    What is the energy stored in the capacitor at t=10 µs?  
Problem 6

 

The switch has been closed for a long time. At time t=1 µs the switch opens.

R1=10 k, R2=R3=1 k, C=2 nF, I0=2 mA and VA=6 V.

Plot VC(t) in the intervall  0<t<7 µs.