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

How is specific gravity defined, How is Specific Gravity defined? Speci...

How is Specific Gravity defined? Specific Gravity, SG, is a unit less quantity that provides the scientist or engineers an idea of how dense a substance is compared to water. T

Pendulum, a pendulum is timed ,first for 20 swings and then for 50 swings ;...

a pendulum is timed ,first for 20 swings and then for 50 swings ; time for 20 swings = 17.4 sec and time for 50 sec = 43.2. calculate the average time per swing/

#title.fraunhoffer diffraction., explain the maxima and minima in fraunhoff...

explain the maxima and minima in fraunhoffer difraction

Experiment of a simple jack screw, A simple jack screw Bore a hole by a...

A simple jack screw Bore a hole by a block of wood to fit a carriage bolt. Choose a bolt that is threaded nearly its whole length. Sink the head of the bolt in the wood, so tha

Can i light a house with a fiber optic, Can I light a house with a fiber op...

Can I light a house with a fiber optic? A house can be light with anything, by candles and gas lamps to fiber optics. However, there is the question, of the efficiency of the s

Simple harmonic motion, composition of two SHM at right angle to each other...

composition of two SHM at right angle to each other and having time period in the ratio of 1: 2

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