Bulb Wattage (P)

Resistance

$R=\frac{V^2}{P}$

Operating voltage (V)

Current (I)

Power dissipated in the filament (P) = I²R

Area of the tungsten filament (A) = 2πrl in m²

6

2400

120

0.05

6

0.0000133095

10

1440

120

0.0833

10

0.0000220462

25

576

120

0.20833

25

0.0000539674

40

360

120

0.33333

40

0.0000395031

60

240

120

0.5

60

0.0000765753

100

144

120

0.8333

100

0.0001154707

200

72

120

1.67

200

0.0001924512

300

48

120

2.5

300

0.0002886768

500

29

120

4.17

500

0.0004947820