Question

Two resistors of 2 ohm and 5 ohms are connected in series. A 12 V source is powering the resistors. The voltage across 5 ohms resistor is

Answer 1

Given

• Two resistors of 2Ω and 5Ω are connected in series
• Voltage = 12 V

To Find

• Potential Difference across the 5Ω resistor

Solution

● In a series connection voltage varies and current is fixed

● In a parallel connection voltage is constant and the current varies

● So now we may use the Ohm's law, which says that V = IR. First find the current of the who connection and then use that to find the current

✭ Net Resistance

→ Rₙₑₜ = R₁ + R₂

→ Rₙₑₜ = 2+5

→ Rₙₑₜ = 7Ω

✭ Current accross the resistors

→ V = IR

→ 12 = I × 7

→ 12/7 = I

━━━━━━━━━━━━━━━━━

✭ Current accross the 5Ω resistor

→ V = IR

→ V = 5 × 12/7

→ V = 8.57 V

Answer 2

Heya !

Given:-

• Resistor 1 = 2ohm.
• Resistor 2 = 5 ohm are connected in series
• Voltage = 12V

To find :-

• Voltage across 5 ohm. resistor.

Formulas to be used :-

• $\huge \fbox \blue{R = R1+R2}$

• $\huge \fbox \blue{I = V/R}$

• $\huge \fbox \blue{V = I × R}$

Putting the given values in the equation:-

Let's find the equivalent Resistance first,

$\implies$ R = R1 + R2

$\implies$ R = 2 + 5

$\implies$ R = 7ohm.

Let's find the value of current now,

$\implies$ I = $\dfrac{V}{R}$

$\implies$ I = $\dfrac{12}{7}$ A.

now,

• We know that voltage across series connection is variable.
• So, to find the Voltage across a particular resistor we need to use the ohm's law. i.e V = I × R

By ohm's law :-

$\implies$ V = I × R

$\implies$ V = $\dfrac{12}{7}$ × 5

$\implies$ V = 8.57 V.