Question

Use the worked example above to help you solve this problem. The amount of charge that passes through a filament of a certain lightbulb in 2.09 s is 1.56 C. (a) Find the current in the bulb. A (b) Find the number of electrons that pass through the filament in 5.24 s. electrons (c) If the current is supplied by a 12.0-V battery, what total energy is delivered to the lightbulb filament

Answer 1

a) i = 0.746 A, b) # _electron = 2.44 10¹⁹ electrons, c) E = 1.87 10⁴ J

Step-by-step explanation:

a) The definition of current is the charge per unit of time

i = Q / t

i = 1.56 / 2.09

i = 0.746 A

b) Let's look for the cargo in passing at this time

i = Q / t

Q = i t

Q = 0.746 5.24

Q = 3.904 C

an electron has a charge e = -1.6 10⁻¹⁹ C, let's use a direct proportions rule

# _electron = 3.904 C (1 electron / 1.6 10⁻¹⁹)

# _electron = 2.44 10¹⁹ electrons

the number of electrons has to be an integer

c) In this part you are asked to calculate the power

P = V i

P = 12 0.746

P = 8.952 W

P = E/t

E = P t

E = 8.952 2.09

E = 1.87 10⁴ J