0195136047.pdf

56 CIRCUIT CONCEPTS

the internal resistance of the amplifier isRS= 8 ,

one has connected a mismatched speaker with

RL= 16 . Determine how much more power

could be delivered to the speaker if its resistance

were matched to that of the amplifier.

1.2.10For the circuit of Figure P1.2.10:

(a) Find an expression for the power absorbed by

the load as a function ofRL.

(b) Plot the power dissipated by the load as a func-

tion of the load resistance, and determine the

value ofRLcorresponding to the maximum

power absorbed by the load.

1.2.11A practical voltage source is represented by an

ideal voltage source of 30 V along with a series

internal source resistance of 1.2. Compute the

smallest load resistance that can be connected to

the practical source such that the load voltage

A

Reυ ⇒

B

2 Ω

3 Ω

8 Ω 4 Ω

2 Ω

4 Ω

Figure P1.2.7

A

B

4 Ω

4 Ω

2 Ω 2 Ω

2 Ω

Figure P1.2.8

Amplifier

(source)

Speaker

(load)

RL VL

RS

−

+

−

+

VS

Figure P1.2.9

Source

500 Ω

Load

VL RL

−

+

+

−

10 V

Figure P1.2.10