Question Number 38967 by rahul 19 last updated on 01/Jul/18
Commented by rahul 19 last updated on 01/Jul/18
$$\:\mathrm{find}\:\mathrm{V}_{\mathrm{a}} −\mathrm{V}_{\mathrm{b}} \:? \\ $$
Commented by rahul 19 last updated on 01/Jul/18
I' m getting correct ans. by Nodal method but when I do by Parallel grouping of cells , I'm getting wrong ans.
Commented by tanmay.chaudhury50@gmail.com last updated on 01/Jul/18
$${they}\:{cell}\:{are}\:{not}\:{parallel}\:{grouped}..{though}\:{it}\:{look}\: \\ $$$${like}\:{parallel}\:{but}\:{pd}\:{across}\:{each}\:{cell}\:{are}\:{not}\:{same} \\ $$
Commented by tanmay.chaudhury50@gmail.com last updated on 01/Jul/18
$${ok}\:{but}\:{tomorrow}…{if}\:{you}\:{want}\:{free}\:{books}\:{to}\: \\ $$$${download}\:{visit}\:{archievs}.{org}… \\ $$
Commented by rahul 19 last updated on 01/Jul/18
Assume R1 internal resistance of E1 and R2 internal resistance of E2.
Then all the cells have same P.D , right ?
Commented by tanmay.chaudhury50@gmail.com last updated on 01/Jul/18
$${i}\:{have}\:{postef}\:{theorem}\:{related}\:{to}\:{cells}\:…{pls}\:\:{purchaze} \\ $$$${resnik}\:{and}\:{haliday}\:{and}\:{dc}\:{pandey}\:{books}…{i}\:{hav} \\ $$$${read}\:{lot}\:{of}\:{physics}\:{books}\:{but}\:{resnik}\:{haliday} \\ $$$${for}\:{concept}\:{and}\:{pandey}\:{for}\:{problems}\:{good}.. \\ $$$${as}\:{per}\:{your}\:{question}\:{if}\:{internal}\:{resistance}\:{then} \\ $$$${parallel} \\ $$$$ \\ $$
Commented by rahul 19 last updated on 01/Jul/18
$$\mathrm{Sir},\:\mathrm{pls}\:\mathrm{solve}\:\mathrm{this}\:\mathrm{q}.\:,\:\mathrm{by}\:\mathrm{parallel}\:\mathrm{grouping} \\ $$
Commented by rahul 19 last updated on 02/Jul/18
$$??? \\ $$
Answered by tanmay.chaudhury50@gmail.com last updated on 04/Jul/18
$${start}\:{from}\:{b}\:\left(−{I}_{\mathrm{1}} {R}_{\mathrm{3}} +{I}_{\mathrm{2}} {R}_{\mathrm{3}} +{E}_{\mathrm{3}} −{I}_{\mathrm{1}} {R}_{\mathrm{2}} −{E}_{\mathrm{2}} =\mathrm{0}\right. \\ $$$$\left(−{I}_{\mathrm{1}} ×\mathrm{4}+{I}_{\mathrm{2}} ×\mathrm{4}+\mathrm{10}−{I}_{\mathrm{1}} ×\mathrm{10}−\mathrm{8}=\mathrm{0}\right. \\ $$$$−\mathrm{14}{I}_{\mathrm{1}} +\mathrm{4}{I}_{\mathrm{2}} +\mathrm{2}=\mathrm{0} \\ $$$${start}\:{from}\:{E}_{\mathrm{1}} \\ $$$${E}_{\mathrm{1}} −{I}_{\mathrm{2}} {R}_{\mathrm{1}} −{E}_{\mathrm{3}} −{I}_{\mathrm{2}} {R}_{\mathrm{3}} +{I}_{\mathrm{1}} {R}_{\mathrm{3}} =\mathrm{0} \\ $$$$\mathrm{6}−{I}_{\mathrm{2}} ×\mathrm{5}−\mathrm{10}−{I}_{\mathrm{2}} ×\mathrm{4}+{I}_{\mathrm{1}} ×\mathrm{4}=\mathrm{0} \\ $$$$\mathrm{4}{I}_{\mathrm{1}} −\mathrm{9}{I}_{\mathrm{2}} −\mathrm{4}=\mathrm{0} \\ $$$${solve}\: \\ $$$$−\mathrm{14}{I}_{\mathrm{1}} +\mathrm{4}{I}_{\mathrm{2}} +\mathrm{2}=\mathrm{0}\:\:×\mathrm{2} \\ $$$$\mathrm{4}{I}_{\mathrm{1}} −\mathrm{9}{I}_{\mathrm{2}} −\mathrm{4}=\mathrm{0}\:\:×\mathrm{7} \\ $$$$\:−\mathrm{28}{I}_{\mathrm{1}} +\mathrm{8}{I}_{\mathrm{2}} +\mathrm{4}=\mathrm{0} \\ $$$$\:\mathrm{28}{I}_{\mathrm{1}} −\mathrm{63}{I}_{\mathrm{2}} −\mathrm{28}=\mathrm{0} \\ $$$$−\mathrm{55}{I}_{\mathrm{2}} +\mathrm{4}−\mathrm{28}=\mathrm{0} \\ $$$${I}_{\mathrm{2}} =\frac{\mathrm{24}}{−\mathrm{55}}\:\:\:\:\:\mathrm{4}{I}_{\mathrm{1}} +\frac{\mathrm{216}}{\mathrm{55}}−\mathrm{4}=\mathrm{0} \\ $$$$\mathrm{4}{I}_{\mathrm{1}} +\frac{−\mathrm{4}}{\mathrm{55}}=\mathrm{0}\:\:\: \\ $$$${I}_{\mathrm{1}} =\frac{\mathrm{1}}{\mathrm{55}} \\ $$$${current}\:{through}\:{R}_{\mathrm{1}} =\frac{\mathrm{24}}{\mathrm{55}} \\ $$$${R}_{\mathrm{2}} =\frac{\mathrm{1}}{\mathrm{55}} \\ $$$${R}_{\mathrm{3}} =\frac{\mathrm{1}}{\mathrm{55}}−\left(\frac{−\mathrm{24}}{\mathrm{55}}\right)=\frac{\mathrm{25}}{\mathrm{55}} \\ $$$${V}_{{a}} \sim{V}_{{b}} ={E}_{\mathrm{3}} −{R}_{\mathrm{3}} \left({I}_{\mathrm{1}} −{I}_{\mathrm{2}} \right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\mathrm{10}−\mathrm{4}×\frac{\mathrm{25}}{\mathrm{55}} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\frac{\mathrm{550}−\mathrm{100}}{\mathrm{55}}=\frac{\mathrm{450}}{\mathrm{55}}=\frac{\mathrm{90}}{\mathrm{11}} \\ $$$${pls}\:{check}\:{is}\:{it}\:{correct}…{if}\:{not}\:{where}\:{the}\:{wrong} \\ $$
Commented by rahul 19 last updated on 04/Jul/18
Correct!
But I asked for parallel grp. method .
Commented by tanmay.chaudhury50@gmail.com last updated on 05/Jul/18
$${ok}\:{pls} \\ $$