Question

the current through a Flashlight bulb is 40 cm and the total battery voltage is 4.5 volt. the resistance of of the bulb is approximately? solve it.............................answer is 112 ohm.
for the brilliant brain................
can you do this open challenge
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Answer 1

Answer:

Resistance of bulb = 112.5 ohms

Step-by-step explanation:

Given,

Current of the bulb, I = 40 mA

We know that,

1000 milli Ampere (mA) = 1 Ampere

1 milli Ampere(mA) = 1/1000 Ampere

So,

Current of the bulb = 40/1000 A

Voltage of the battery = 4.5 V

We know, that by ohm's law,

Resistance(R) =

= Voltage(V)/Current(I)

=> R = V/I

By applying the values, in the equation, we get,

=> R = 4.5/(40/1000)

=> R = (4.5×1000) / 40

=> R = 4.5 × 25

=> R = 112.5 ohms

Hence,

The resistance of of the bulb =

= 112.5 ohms