Please answer this question

Asked by tanyajain164 | 22nd Jan, 2022, 09:44: AM

Expert Answer:

Given circuit is redrawn in fig.(1) for better understanding .
As can be seen from fig.(1) , resistors R2 , R3 and R4 are shorted at B and C .
 
Further, ends of resitor R3 are dircectly connected to terminal points of battery at A and D.
 
Hence there will not be any current flow in resistors R2 and R4 . Hence they can be removed in the circuit .
 
Fig(2) shows the final circuit after removing R2 and R4 .
Equivalenet resistance of the circuit is series combination of R1 and R5 in parallel to R3 .
 
Req = ( R1 + R5 ) || R3  = [ (6 + 6 ) || 12 ] Ω  = 6 Ω
 
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(1) Equivalent resistance of circuit is 3 Ω
 
Above statement is false because , we have calculated the equivalent resistance as 6 Ω
 
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(2) Current flow through R3 is 4 A
 
Above statement is false because as seen from fig(1) and fig(2) , resistor R3 = 12 Ω  is connected directly to 12 V battery .
Hence current flowing through R3 is 1 A
 
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(3) Voltage drop across R1 is 6 V
 
Above statement is true as explained below.
 
Resistors R1 and R5 are in series and directly connected to 12 V battery [ Refer fig(1) and fig (2) ]
 
Hence current flow through R1 and R5 = [ 12 V / ( 6 + 6 ) Ω ] = 1 A 
 
Hence potential drop across R1 = ( 6 × 1 ) = 6 V
 
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(4) Current flow through R2 = 1 A
 
Above statement is false , current does not flow through R2

Answered by Thiyagarajan K | 22nd Jan, 2022, 11:37: AM