Question

Compute the no. Of electrons passing per min. Through an electric bulb of 60w 220v

Answer 1

Given :-

▪ An electric bulb that operates at 60 W 220 volt.

To Find :-

▪ Number of electrons passing per minute through th bulb.

Solution :-

First, Let us find the current passing through the bulb in one minute.

We have,

• Potential difference, V = 220 volt
• Power, P = 60 watt

Using the following formula, Current, I can be calculated as,

⇒ P = V × I

⇒ 60 = 220 × I

⇒ 60/220 = I

⇒ 6/22 = I

⇒ I = 0.27 A

So, 0.27 A of current is flowing through the bulb in one minute. Now, let us find the quantity of charge flowing in one minute using current.

Which can be calculated as,

⇒ I = Q / t

⇒ 0.27 = Q / 60 [ 1 minute = 60 seconds ]

⇒ Q = 16.2 coulomb

We know, 1 coulomb of charge is contained in 6.25 × 10¹⁸ electrons.

So, In 16.2 coulomb,

⇒ No. of electrons = 16.2 × 6.25 × 10¹⁸

⇒ No. of electrons = 101.25 × 10¹⁸

Hence, 101.25 × 10¹⁸ electrons are passing through the bulb in one minute.

Answer 2

Power (P) = 60 W

Voltage (V) = 220 V

$\boxed{ \rm{Current(I) = \frac{Power(P)}{ Voltage(V)}}}$

$\rm I = \dfrac{60}{220}$

$\rm I = 0.27 \: A$

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

Time (t) = 1 minute = 60 s

$\boxed {\rm{Charge (Q) = Current(I) \times Time(t) }}$

$\rm Q=0.27 \times 60$

$\rm Q=16.2 \: C$

　　　　　　　　　　　　　　　　

$\sf Electrons \: in \: 1C \: charge = 6.25 × 10</p><p>$

$\sf 1C \:of~ charge = 6.25 × {10}^{18}~electrons$

　　　　　　　　　　　　　　　　

$\sf 16.2C \: Charge =16.2 \times 6.25 × {10}^{18} electrons$

$\sf {\underline{\underline{16.2C \: Charge = \red{101.25 × {10}^{18}}~electrons.}}}$