JSunil sir
When electric current flows through a resistor, like a wire, some of the electrical energy is converted into heat energy. This phenomenon is known as Joule's heating effect.
The heat produced is proportional to the square of the current flowing through the resistor and the resistance of the resistor.
In simple terms, the more current that flows through a resistor, or the higher its resistance, the more heat it generates.
This effect has various practical applications.
For example, electric heaters and toasters use Joule's heating effect to produce warmth and cook food.
However, this effect can also lead to energy loss in electrical systems, which is why it's important to use efficient materials and designs to minimize such losses.
Questions ❤️
If the current through a resistor is increased by 100% (doubled), the increase in power dissipated will be ....?
Ans : 300%. This is because the power (P) dissipated in a resistor is given by the formula:
If the current is increased by 100%, the new current becomes 2I . Plugging this into the formula:
P =I2R
P_new = (2I)^2
R = 4^2 R
The increase in Power = 4I^2 R - I^2 R = 3I^2 R
This increase in power is 3 times the initial power (P), which means it's a 300% increase.
Check your knowledge
1. What is Joule's heating effect?
a) The cooling effect of electric current
b) The magnetic effect of electric current
c) The conversion of electric energy into heat energy
d) The generation of light from electric current
2. Which factors determine the amount of heat produced by Joule's heating effect?
a) Voltage and resistance
b) Voltage and current
c) Current and resistance
d) Voltage, current, and resistance
3. If the resistance of a wire is doubled while keeping the current constant, how does the heat produced change?
a) It becomes half
b) It becomes double
c) It remains the same
d) It increases four times
4. An electric heater converts electrical energy into:
a) Light energy
b) Sound energy
c) Heat energy
d) Mechanical energy
5. Which of the following devices uses Joule's heating effect to function?
a) Solar panel
b) Loudspeaker
c) Electric fan
d) Incandescent bulb
Certainly! Here are some additional questions to help test your understanding of the relationship between current, power, and resistance in electrical circuits:
1. If the current through a resistor is halved, how does the power dissipated change?
a) It becomes half
b) It becomes one-fourth
c) It remains the same
d) It doubles
2. A resistor with a resistance of 10 ohms has a current of 2 amperes passing through it. What is the power dissipated?
a) 20 W
b) 40 W
c) 10 W
d) 4 W
3. A resistor is connected to a 12-volt battery. If the power dissipated is 48 watts, what is the current passing through the resistor?
a) 2 A
b) 4 A
c) 6 A
d) 8 A
4. If the resistance of a wire is kept constant and the voltage across it is doubled, how does the power dissipated change?
a) It becomes half
b) It becomes double
c) It becomes four times
d) It remains the same
5. Which of the following formulas represents the relationship between power (P), current (I), and resistance (R)?
a) P = IR
b) P = I/R
c) P = I^2 R
d) P = R/I
Happy Learning!
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