Question

A torch bulb is rated at 1.5 V, 500 mA. Find its resistance.

Answer 1

SoluTion :

✴ Given :-

• P.d across torch bulb = 1.5V
• Current flow = 500mA

✴ To Find :-

• Resistancd of torch bulb

✴ Concept :-

✈ As per ohm's law, 'current flow in conductor is directly proportional to the potential difference across conductor.'

Mathematically,

$\bigstar\:\boxed{\sf{\pink{\large{V=I\times R}}}}$

• V denotes potential difference
• I denotes current flow
• R denotes resistance

✴ Conversation :-

✒ 500mA = 0.5A

✴ Calculation :-

$\implies\sf\:R=\dfrac{V}{I}\\ \\ \implies\sf\:R=\dfrac{1.5}{0.5}\\ \\ \boxed{\sf{\orange{\large{R=3\:\Omega}}}}$

____________________________

▶ Resistance of torch bulb = 3Ω

Answer 2

Answer:

3 Ω

Explanation:

Given :

Potential difference V = 1.5 V

Current I = 500 mA

Current in term of A :

I = 500 × 10⁻³ A

= > I = 0.5 A

We are asked to find resistance R :

From ohm's law we know :

V = I R

= > R = V / I

Putting values here we get :

= > R = 1.5 / 0.5 Ω

= > R = 3 Ω

Hence we get required answer!