Electrical Engineering - Series-Parallel Circuits - Discussion

Discussion Forum : Series-Parallel Circuits - General Questions (Q.No. 4)
4.
A certain voltage divider consists of two 12 k resistors in series. Which of the following load resistors will have the most effect on the output voltage?
1 M
24 k
18 k
12 k
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
18 comments Page 1 of 2.

Harpreet said:   1 decade ago
By ohm's law V=IR
I=V/R

SO CURRENT INVERSELY PROPORTIONAL TO THE RESISTANCE

Hence less will be resistance more is the current flowing so more voltagee dropped and low resistance will more effect on output voltages.

So answer is D

HARPREET SING H said:   1 decade ago
BY OHM LAW.

Inversally proportional to the resistance so less will be the resistance more will be the current hence less valued resistane effectt more voltage output.

SO ANSWER IS D=12.

Anand said:   1 decade ago
Nice explanation Harpreet singh

Venki said:   1 decade ago
If the value of resistanace more, the voltage drop is high hence o/p voltage reduced.

Chaitu said:   1 decade ago
Thank You Harpreet Sing

GOPI REDDY said:   10 years ago
Inversely proportional to the resistance so less will be the resistance more will be the current hence less valued resistance effect more voltage output.

By ohm's law V = IR.
I = V/R.

VIPIN CHAUHAN said:   10 years ago
In voltage divider we take parallel of one of series resistance with load resistance. Now if we take load resistance equal than parallel of two will be half of one of the series resistance which will be minimum and hence affect the voltage more.

Chandana priya said:   9 years ago
We know that from ohm's law if current increases voltage also increases. So if resistance decreases current increases. 12k+12k gives 24k.

In parallel resistance decreases. So 12k is more appropriate for less resistance. So more voltage.

ROOPESH said:   9 years ago
The correct answer is D.

The answer cannot be A or C, because they given that two 12k resistors are in series, so 1M and 18K doesn't come into picture.

Now the answer may be 12K or 24K.

A voltage divider circuit must contain at-least two loads and we should take output across any one load. If we take voltage across total load then it is not called a voltage divider circuit.

So in this problem we should take voltage across any 1 12K resistor. Hence 12k resistor only can have effect on output voltage.

Ramya said:   9 years ago
The load resistor is connected across any one 12k resistor.

Now consider 1M resistor is connected across 12k then total resistance become 8K.
Now consider 24K resistor is connected across 12k then total resistance become 11.85k.
Now consider 18k resistor is connected across 12k then total resistance become 7.2k.
Now consider 12k resistor is connected across 12k then total resistance become 6k.

So out of 8k, 11.85K, 7.2K and 6K, the voltage across 6k is small.

So this resistor reduces the output voltage. So 12k resistor have the more effect on output voltage.

If we connect 12k load resistor then output voltage reduces to low value, compared to other load resistance value.


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