Electronics - Series-Parallel Circuits - Discussion
Discussion Forum : Series-Parallel Circuits - General Questions (Q.No. 32)
32.
In a series–parallel circuit consisting of R1 and R2 in series and connected in parallel with R3, if R1 opens, then R2's voltage will:
Discussion:
10 comments Page 1 of 1.
PUNIT said:
1 decade ago
Hi Friends.
If we take r1=2, r2=3 & r3=4.
Then,
r1+r2 = 5 //With r3 find value total resistance.
RT = 2.22.
Image current flow is 1 amp.
Then voltage is V = ir = 1*2.22 = 2.22 v.
If r1 is open, then find voltage r2/r3 = 1.714.
Current is 1 amp.
So V = IR 1.714*1 = 1.741 v.
Voltage decrease B is correct.
Thanks.
If we take r1=2, r2=3 & r3=4.
Then,
r1+r2 = 5 //With r3 find value total resistance.
RT = 2.22.
Image current flow is 1 amp.
Then voltage is V = ir = 1*2.22 = 2.22 v.
If r1 is open, then find voltage r2/r3 = 1.714.
Current is 1 amp.
So V = IR 1.714*1 = 1.741 v.
Voltage decrease B is correct.
Thanks.
Phoenix said:
9 years ago
There is a finite potential drop across r2 when r1 is present.
There is no potential drop across r2 once r1 is open (since no current flows through r2) i.e voltage of r2 is now zero.
Hence, the voltage decreases (from a finite value to zero).
There is no potential drop across r2 once r1 is open (since no current flows through r2) i.e voltage of r2 is now zero.
Hence, the voltage decreases (from a finite value to zero).
Murali said:
1 decade ago
Always current tries to flow through low resistance path. Suppose if r1 is opened then resistance through that path is ideally infinity.
So no current will flow through that path. So voltage across r2 is zero. Not decreases.
So no current will flow through that path. So voltage across r2 is zero. Not decreases.
Radhakrishna said:
10 years ago
@Punit is wrong.
If R1 is open how R2 and R3 become parallel net resistance is R3.
So V=IR, = 1*4 = 4. So voltage across R3 increases and hence R2 which is a point on R3 also increases.
If R1 is open how R2 and R3 become parallel net resistance is R3.
So V=IR, = 1*4 = 4. So voltage across R3 increases and hence R2 which is a point on R3 also increases.
Abdul Haleem said:
1 decade ago
If R1 and R2 are in series, and R1 gets open, then there will be "no voltage" across R2.
Answer should be "no voltage" instead of "decreases".
Answer should be "no voltage" instead of "decreases".
Jigar said:
1 decade ago
Is it because once the resistance is removed, circuit becomes open and no current flows through it, and so no voltage drop?
Pranjal said:
10 years ago
If r1 will open then r2 become as load resister because its parallel.
Then how there is no voltage drop?
Explain please.
Then how there is no voltage drop?
Explain please.
Rashee said:
1 decade ago
But as there is no voltage drop voltage should remain same.
Mohamed sherif said:
1 decade ago
r1 open then no current flow so no voltage across r2.
Mohiddin said:
1 decade ago
Thanks jigar.
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