English

Write Joule's law of heating.

Advertisements
Advertisements

Questions

Write Joule's law of heating.

 State and explain Joule's law of heating.

Answer in Brief
Advertisements

Solution

Joule's law of heating: When a current (I) flows through a resistor of resistance (R) for time (t), then the amount of heat produced (H) is given by 

H = I2Rt

This is known as Joule’s law of heating.

shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Electricity - Exercise 8 [Page 258]

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

When current is switched ‘on’ in a room heater, it ______.


How does the resistance of a wire vary with its: 

 diameter? 

 


Why does the connecting cord of an electric heater not glow hot while the heating element does?


The elements of electrical heating devices are usually made of:

(a) tungsten
(b) bronze
(c) nichrome
(d) argon


The electrical resistivities of four materials P, Q, R and S are given below:

P `6.84xx10^8`Ωm
Q `1.70xx10^8`Ωm  
R ` 1.0xx10^15`Ωm
s  `11.0xx10^-7`Ωm  

Which material will you use for making: (a) heating element of electric iron (b) connecting wires of electric iron (c) covering of connecting wires? Give reason for your choice in each case.

 


Which electric heating device in your home do you think have resistors which control the flow of electricity?


Give Scientific reason.

In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.


Identify the figure and give its use.


Solve the following example.

Two tungsten bulbs of wattage 100 W and 60 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor? 


Find the odd one out and give its explanation.


Name any two appliances which work under the principle of heating effect of current.


A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross-section of the filament in 16 seconds would be roughly:


The heating element of an electric iron is made up of:


Assertion: Bending of wire decreases the resistance of the electric wire.

Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.


An MCB can be used instead of a fuse in an electrical circuit.


What are the factors affecting heating effect of electric current?


Explain the working of an electric fuse.


If 220 V potential difference is applied across an electric bulb, a current of 0.45 A flows in the bulb. What must be the power of the bulb?


What is the heating effect of electric current?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×