Explain how to calculate constant voltage source, Physics

Assignment Help:

Power is to be supplied from a source whose resistance is 20 K ? to a load of 100 ?. Would you consider it as a constant voltage source or current source? Explain.

Ans.

Given source is considered as a constant current source because, a source that has a very high internal resistance (20 K?) as compared to the load resistance (100 ?) is a constant current source.

Explanation: In figure below, a load impedance ZL is connected to a current source. Let It be the short-circuit current of source, and Zs be its internal impedance. Current IS is splitted into two parts IL through ZL and I1 through ZS. That is

 

1939_electronics.png

 

IS= I1+ IL

Or        I1= IS- IL

Because impedance Zs and  ZL are  in  parallel,  voltage  drop  across each must be equal, i.e.,

1145_equation.png

The above equation determines us that load current IL would remain almost the same as current IS, provided the ratio ZL/ZS= 100/20000 = 1/200 is small compared to unity. Source then behaves as a good current source.  Or we can say, the larger the value of internal impedance ZS (20K?) compared to load impedance ZL (100?), the smaller is the ratio ZL/ZS, and better it works as a constant current source.

 

 


Related Discussions:- Explain how to calculate constant voltage source

Explain centripetal force, Explain Centripetal force?? Sir Isaac Newton...

Explain Centripetal force?? Sir Isaac Newton suggested that motion in a straight line is most natural, and that deviations from this type of motion are caused by a force pullin

What is the velocity of the ball - magnitude and direction, A boy is standi...

A boy is standing on an elevator which is travelling downward with constant velocity of 30 meters per second.  The boy throws a ball vertically upward with velocity of 10 meter

fraction of vacancy sites at double the temperature, The fraction of vacan...

The fraction of vacancy sites in a metal is 1X10 -10 at 500 0 C.  What will be the  fraction of vacancy sites at double the temperature?

Compton effect and quantum nature of light, Q.   Describe Compton effect. D...

Q.   Describe Compton effect. Drive an expression for Compton shift. How does it support the particle nature of light.  Compton Effect and Quantum Nature of Light A.H. Com

Determine the focal length of the lens, Q. A screen is placed 90 cm from an...

Q. A screen is placed 90 cm from an object. The image of the object on the screen is formed by a convex lens at two different locations separated by 20cm. Determine the focal lengt

Find entropy change in the mixing process, 1.5 kg of Oxygen (N 2 ) and 0.15...

1.5 kg of Oxygen (N 2 ) and 0.15 kg of Helium (He 2 ) are separated by a partition in a vessel.  The Nitrogen is at 5 bar and 90 o C and the Helium at 1 bar and 20 o C.  The part

Advantages of integrated circuits over conventional circuits, Advantages of...

Advantages of Integrated Circuits (ICs) over conventional circuits: (1)  Very small size- thousand times smaller than discrete circuit. (2)  Very small weight due to miniatu

How many ports does a fiber optics system have, How many ports does a fiber...

How many ports does a fiber optics system have? Depending upon the final use the main common parts to account for in a fundamental system are: bushing, end fittings and illumin

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd