Question

What is the filament resistance of a 220 volt - 60 watt bulb when connected to a 220 volt main switch?​

Answer 1

the required answer is 806.67 ohm

GIVEN:

• potential difference, v= 220 volt

• power,p= 60 watt

TO FIND:

the filament resistance of bulb,R

FORMULA:

power, P=V^2/ R

KEYS:

• p......power
• R...... resistance
• V........ potential difference

SOLUTION:

$p = \frac{ {v}^{2} }{R} \\ \\ 60 = \frac{ {220}^{2} }{R} \\ \\ R = \frac{48400}{60} \\ \\ R= 806.666 \\ \\ R= 806.67 \: ohm$

ANSWER:

the filament resistance of bulb ,R = 806.67 ohm

RELATED FORMULAE:

• V=IR

• P=V^2/R

• P=I^2(R)

FACT RELATED TO QUESTION:

PURPOSE OF RESISTANCE:

• resistor is a device that offers resistance to the flow of current.

• resistor is available in many forms .Example: carbon resistor, resistance filament

• the current flow must be resisted to avoid damage of the device