Control System Unit 1 and 2

Traffic light system is the example of:

• a) Open-loop system

• b) Closed-loop system

• c) Both (a) and (b)

• d) None of these

The negative feedback closed-loop system was subjected to 15V. The system has a forward gain of 2 and a feedback gain of 0.5. Determine the output voltage and the error voltage

• 15V, 10V

• 6V, 5V

• 15V, 7.5V

• 5V, 10V

Answer explanation

Given:

G(s) = 2

H(s) = 0.5 and R(s) = 10V

Output voltage:

= (2/1+2x 0.5) x 15 = 15V

Error voltage:

= (1/1+2x 0.5) x 15 = 7.5V

Hence the correct answer is option (c).

Find the function f(t) for the following function F(s):

• 0.25e^-t+0.05e^-5t

• -0.2-0.25e^-t+0.05e^-5t

• -0.2+0.25e^-t+0.05e^-5t

• 0.25e^-5t+0.05e^-t

The force equation of the given system is:

• 
• 
• 
• 

Determine the transfer function of the given system:

• G1G2G3/ (1 + H2G2G3 + G2G1H1)

• G1 G2G3/ (1 + G1G2G3H2H1)

• G1G2G3 / (1 + G1G2G3H1 + G1G2G3H2)

• G1G2G3 / (1 + G1G2G3H1)

Find the overall transfer function of the given signal flow graph.

• G1G2G3/ (1 + G1H1 + G3H2 + G3G1H1H2)

• G1G3/ (1 + G1H1 + G3H2 + G3G1)

• (G1G2G3 + G1H1)/ (1 + G1H1 + G3H2 + G3G1H1H2)

• (G1G2G3 + G1H1 + G3H2) / (1 + G1H1 + G3H2 + G3G1H1H2)

The signal flow graph shown in the figure has:

• forward path = 2, loops = 4, and non-touching loops = 0

• forward path = 3, loops = 4, and non-touching loops = 0

• forward path = 3, loops = 3, and non-touching loops = 0

• forward path = 2, loops = 4, and non-touching loops = 2

Arrange the following set of statements in order.

1. By marking all the forces acting on the node

2. Drawing each mass separately.

3. Take Laplace transform of differential equations and rearrange the equations in the s-domain.

4. Find the transfer function as the ratio between output and input variable.

5. Write one differential equation for each of the free body diagram.

• 1, 2, 3, 4, 5

• 2, 1, 5, 3, 4

• 1, 3, 2, 5, 4

• 2, 1, 4, 3, 5

Use mason’s gain formula to find the transfer function of the following signal flow graph:

• abcd+efg/1-cd-fg-cdfg

• acdfg+bcefg/1-cd-fg-cdfgg

• abef+bcd/1-cd-fg-cdfg

• adcdefg/1-cd-fg-cdf

Use mason’s gain formula to find the transfer function of the given figure:

• G1+G2

• G1+G1/1-G1H+G2H

• G1+G2/1+G1H+G2H

• G1-G2