NCERT Solutions For Class 10 Science Electricity

 NCERT Solutions Electricity 

In text Questions 

Page 200 

1. What does an electric circuit mean?
.👉 A continuous and closed path of an electric current is called an electric circuit. 

2. Define the unit of current.

👉 The SI unit of electric current is ampere (A). When 1 coulomb of charges flows through any cross-section of a conductor in 1 second, the current flowing through it is said to be 1 ampere. 

3. Calculate the number of electrons constituting one coulomb of charge.

👉  Charge of an electron `= 1.6 × 10^{-19}`C. 

             `1.6 × 10^{-19} × n = 1`C

          ` ⇒ n = frac{1}{1.6 × 10^{-19}}`

           `⇒ n =  frac{10^{20}}{16}`

     ` ⇒n =  0.0625 × 10^{20}`

       ` ⇒ n = 6.25 × 10^{18}`

Page 202

1. Name a device that helps to maintain a potential difference across a conductor.

👉 An electric cell (or a battery)

2. What is meant by saying that the potential difference between two points is 1 V?

👉 One volt is the potential difference between two points in a current-carrying conductor when 1 joule of work is done to move a charge of 1 coulomb from one point to the other.

1 volt = 1 joule / 1 coulomb  

`1 V =  1J C^{-1}`

3. How much energy is given to each coulomb of charge passing through a 6 V battery?
👉   `W = ?`
   `V = 6V`
    `Q = 1C`

` V = W/Q`

`⇒ W = VQ`

`⇒ 6 × 1 = 6J`