Physics
A car bulb connected to a 12 volt battery draws 2 A current when glowing. What is the resistance of the filament of the bulb? Will the resistance be more, same or less when the bulb is not glowing.
Current Electricity
84 Likes
Answer
Given,
Potential difference (V) = 12 V
Current (I) = 2 A
Resistance = ?
From Ohm's law
V = IR
Substituting the values in the formula above, we get,
Hence, the resistance of the filament of the bulb = 6 Ω
The resistance will be less when the bulb is not glowing.
Answered By
56 Likes
Related Questions
A current of 3.2 mA flows through a conductor. If charge on an electron is -1.6 x 10-19 coulomb, find the number of electrons that will pass each second through the cross section of that conductor.
Find the potential difference required to flow a current of 300 mA in a wire of resistance 20 Ω.
In an experiment of verification of Ohm's law, following observations are obtained.
Potential difference V (in volt) 0.5 1.0 1.5 2.0 2.5 Current I (in amp) 0.2 0.4 0.6 0.8 1.0 Draw a V-I graph and use this graph to find —
(a) the potential difference V when the current I is 0.5 A.
(b) the current I when the potential difference V is 0.75 V.
(c) the resistance in circuit.
Two wires of the same material and same length have radii 1 mm and 2 mm respectively. Compare (i) their resistances (ii) their specific resistance.