16. Two electric bulbs marked 100W 220V and 200W 200V have tungsten filament of same length. Which of the two bulbs will have thicker
filament?
​

The second bulb will have thicker filament

Explanation:

Given;

First electric bulb: Power, P₁ = 100 W and Voltage, V₁ = 220 V

Second electric bulb: Power, P₂ = 200 W and Voltage, V₂ = 200 V

Resistivity of tungsten, ρ = 4.9 x 10⁻⁸ ohm. m

Resistance of the first bulb:

Resistance of the second bulb:

Resistivity of the tungsten filament is given by the following equation;

where;

L is the length of the filament

R is resistance of each filament

A is area of each filament

where;

r is the thickness of each filament

Therefore, the second bulb will have thicker filament

more than, less

less than, more

radiation

explanation:

heat is transmitted by radiation