Advertisements
Advertisements
प्रश्न
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
उत्तर
The amount of heat (H) produced is given by the joule’s law of heating as H = Vlt
Where,
Current, I = 5 A
Time, t = 30s
Voltage, V = Current × Resistance
= 5 × 20
= 100 V
H = 100 × 5 × 30
= 1.5 × 104 J.
Therefore, the amount of heat developed in the electric iron is 1.5 × 104 J.
APPEARS IN
संबंधित प्रश्न
State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery?
Why does the cord of an electric heater not glow while the heating element does?
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
Name any two effects of electric current.
Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for your answer.
Give a scientific reason.
For electric power transmission, copper or aluminium wire is used.
Give scientific reason :
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster, etc., an alloy such as Nichrome is used, not pure metals.
Name any six domestic appliances based on the heating effect of electric current.
Which of the following substance contracts on heating?
Find the odd one out and give its explanation.
What is the heating effect of electric current?
What is overloading?
When does overloading occur?
What does overloading cause?
An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?
Unscramble the following words:
SFEU
Explain the working of an electric fuse.
What is the heating effect of electric current?
