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Wednesday, November 9, 2022

All Formulas of Chapter Electricity Class 10

 All Formulas of Chapter Electricity Class 10 |Class 10 Science Electricity Formulas

In this article, we will discuss all formulas of chapter electricity class 10. Chapter 12 electricity belongs to Physics. Here you will find all formulas of electricity class 10 NCERT.

Class 10 Science Electricity Formulas
All Formulas of Chapter Electricity Class 10

Numerical questions are asked in the examinations based on all formulas of electric current class 10. You must learn these all formulas. You will find examples based on class 10 physics chapter electricity formulas.


Physical quantity, symbols, and units

Physical quantity


Unit (S.I.)

Electric current


Ampere (A)



Coulomb(C )






Ohm (Ω)

Potential difference


Volt (V)



Joule (J)




Area of cross-section


Meter square(m2)

Resistivity/specific resistance


Ohm ×meter(Ωm)



Watt (W)



Joule (J)


First, you should note down the formulas and learn them, after that go through the examples given below.

So after reading the above list of physical quantities, symbols, and their units, you can easily learn the physics electricity formulas

 All formulas of Physics Class 10

1.Electric current 


`I=frac\{n e}{t}`    [Q = ne]

Where n= number of electrons

    e= charge on electron = `1.6 ×10^-19` Coulomb

2. Potential difference

`V=  frac\{W}{Q}`

3. Resistance of a conductor


4. Potential difference


5. Electric current 


6. Resistivity or specific resistance


7. Total or equivalent resistance

`R=R_1+ R_2+R_3+⋯..R_n`[series combination]

`frac\{1}{R}= frac\{1}{R_1} +  frac\{1}{R_2 }+  frac\{1}{R_3} +⋯..1/R_n`    [Parallel combination]

8. Power 

`P=frac\{W}{t}`      [W=VQ]

`P=frac\{VQ}{t}`    [`frac\{Q}{t}=I`]

P=VI                        [V=RI]

`P=I^2 R`                [`I=frac\{V}{R}`]


9. Heat produced 

`H=I^2 Rt`


So, these are the all formulas of electricity. Before we start solving numerical questions based on the formula related to electricity class 10, we will discuss the different components used in an electric circuit.

Electric Components Symbols Class 10 Science

All Formulas of Chapter Electricity Class 10

Chapter 12 Physics Class 10 Numericals

Now we will solve some numericals from electricity class 10

    1. If a 10 C charge is passing through a point in 2 seconds in an electric circuit. Find the electric current passing through the conductor.

Solution: -

Given values

Charge (Q) =10C

Time (t) = 2 s

Electric current (I)=?



`I=  frac\{10}{2}`=5 A         


   2.  A current of 1 A is drawn by a filament of an electric bulb. Find the number of electrons passing through a cross-section of the filament in 16seconds.


Given values

Current (I) = 1A

Time (t)= 16s

The number of electrons (n)=?

  `I=frac\{n e}{t}`    

`n=frac\{It}{e} =  (1 ×16)/(1.6 ×10^(-19) )`


3.How much work is done in carrying 10 C charge from point A and point to B if conductor is connected 6 Volt battery.

Solution :-

Given values

Charge (Q)= 10C

Voltage (V)= 6v

Work (W)= ?

`V= frac\{W}{Q}`


  W=10×6=60 J

4.When a conducting wire is connected to 10 volt battery receives 5 amp current, find the resistance of the wire.

Solution :-

Given values

Potential difference (V)= 10 volt

Current (I)= 5 amp

Resistance (R) = ?


`R=frac{10}{5}`=2 Ω

5.An electric immersion rod draws a current of 5 A when it is connected to 110 V. What current will the heater draw when it is connected to 220V.


Given values 

Electric current (I)= 5A

Potential difference (V)= 110 V

According to Ohm’s law


110=5 ×R 


Now when the voltage is 220 V

220=I ×22 

`I= frac\{220}{22}=10 A`   

6. Find the specific resistance of wire having a length of 1 m and an area of cross-section 1.20 × 10-6m2, if the resistance of a wire is 0.015 Ohm.

Solution: -

Given values 

Length (L)= 1m

Area of cross-section (A)= 1.20 × 10-6m2

Resistance ( R)=0.015 Ohm

Specific resistance (P) =?

We know that 


`ρ=frac\{(0.05× 1.20 ×10^(-6)  )}{1}=0.06 ×10^(-6)` 


`ρ=6 ×10^(-8)` Ωm 

7. Find the total or equivalent resistance of a circuit in which three resistors of 5Ω,10Ω, and 15Ω are connected in a series combination.

Solution: -

Given values

R1= 5Ω

R2= 10Ω

R3= 15Ω

Total resistance (R) =?

We know total resistance in series combination is 

R= R1+R2+R3

R= 5 + 10 +15 = 30 Ω

8. Three resistance of 5 Ω, 10 Ω, and 10Ω are connected in parallel combination, find the total resistance of the circuit.


Given values 

R1= 5Ω

R2= 10Ω

R3= 10 Ω

We know that total resistance in parallel combination 

`frac\{1}{R}=  frac\{1}{R_1} +  frac\{1}{R_2} + frac\{1}{R_3}`  

`frac\{1}{R}=  frac\{1}{5}+  frac\{1}{10}+frac\{1}{10}` 

`frac\{1}{R}=  frac\{(2+1+1)}{10}=  frac\{4}{10}` 

`R=  frac\{10}{4}`=2.5Ω 

9.A bulb takes 5 A from a 220 V line. Determine the power of the bulb.


Given values 

Voltage (V)= 220V

Current (I)= 0.5A

Power (P)=?


P=220 ×0.5= 110W

10.Two bulbs , one rated 100W at 220V and the second 60W at 220V , which bulb draws high current.

Solution: -

Given values 

For the first bulb

P1= 100W

V1= 220V

For the second bulb


V2= 220V

Current drawn by the first bulb

`P_1=V_1 I`  

110=220 ×I 


Current drawn by the second bulb

`P_2=V_2 I`  

110=220 ×I 


The first bulb draws more current than the second bulb

11.Resistance of filament of bulb is 10 Ω draws electric current 5 A. What is the power of the bulb?

Solution: - 


Resistance (R) =10Ω

Current (I)= 5A

Power (P) =?

`P=I^2 R` 


12.1kJ heat is produced each second in 20 Ω resistance. Find the potential difference across the resistor.

Solution: - 

Given values

Heat (H)= 1kJ= 1000J

Time (t)= 20 Ω

Potential difference (V)=?

We know 

`H=I^2 Rt` 

`1000=I^2 × 20 ×1`

`I^2=  1000/20`=50A 

`I=√50=7.07 A` 

So, the potential difference across the resistor


V= 7.07 × 20= 141.40 V

So these are the physics electricity formulas and numerical questions based on these electricity formulas class 10.

Frequently Asked Questions

1. What is electricity formula?

Ans. Chapter 12 Electricity consists of various formulas to find different values like - electric current, potential difference, power, heat, resistance, etc.

2. What are the three formulas for electric current?

Ans.  `I=frac\{Q}{t}`      

3. Why study chapter 12 electricity class 10 science?

Ans. Chapter 12 is related to Physics class 10 science and it consists of Ohm's law, resistance, power, and other physical values. Numerical questions are asked in the CBSE board exams, so must learn and study this chapter.



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