Question

What happens to the current in a circuit if a 10 ohm
resistor is removed and replaced by a 20 ohm resistor?
​

Answer 1

Answer:

current will be halved.

Explanation:

Let voltage V is same in both the cases.

So in first case:

i=v/10

in second case:

i'=v/(2*10)

so i'=i/2

Answer 2

Given,

In a circuit, a 10 ohms resistor is removed and replaced by a 20 ohms resistor.

To Find,

What happens to the current?

Solution,

We can solve the question as follows:

It is given that a 10 ohms resistor is removed and replaced by a 20 ohms resistor. We have to find the change in current.

Let the voltage be equal to V. Let the current passing through the 10 ohms resistor be I and the current passing through the 20 ohms resistor be I'.

$Voltage = V$

$Current\: through\: 10\: ohms = I$

$Current\: through\: 20\: ohms = I'$

According to Ohm's Law, the voltage across an inductor is equal to the current multiplied by the resistance through it.

$V = IR$

In the first case,

$V = I*10$

$I = \frac{V}{10}$

In the second case,

$V = I'*20$

$I' = \frac{V}{20}$

Dividing I' by I,

$\frac{I'}{I} = \frac{V/20}{V/10}$

$\frac{I'}{I} = \frac{1}{2}$

$I' = \frac{1}{2} I$

The current decreases by 1/2 or half.

Hence, the current decreases by half when the 10 ohms resistor is placed with a 20 ohms resistor.