Electric Power

Step 1: Understanding the Concept:
For AC, power . .

Step 2: Detailed Explanation:



Step 3: Final Answer:
Power = .

Step 1: Understanding the Concept:
Energy dissipated per unit time is power. For a resistor, power can be calculated using .

Step 2: Detailed Explanation:
Given: Resistance of wire, . Voltage of battery, . Assuming the wire is connected directly across the battery (no internal resistance mentioned), the power dissipated is:

Step 3: Final Answer:
The energy dissipated per unit time is .

Step 1: Identify the given information and the formula for heat developed.
Given: - Resistance of the first resistor, . - Voltage of the battery, . - Time, . The formula for heat (Joule's heating) developed in a resistor is given by: Since the voltage across the resistor is known, the formula is the most direct to use.

Step 2: Determine the voltage across resistor .
The resistors and are connected in parallel to the battery. In a parallel circuit, the voltage across each component is the same as the voltage of the source. Therefore, the voltage across is:

Step 3: Convert time to SI units.
The time is given in minutes, which needs to be converted to seconds for consistency in SI units.

Step 4: Calculate the heat developed in .
Substitute the values of , , and into the heat formula: The heat developed in resistor in one minute is 800 Joules.

Final Answer: (B) 800 J

Step 1: Understanding the Concept:
When an electric current flows steadily through a conductor across a specific potential difference, electrical work is done.
This work is entirely dissipated into the surrounding environment as thermal energy, a phenomenon widely known as Joule's heating effect.
Step 2: Key Formula or Approach:
The total heat developed in a conductor over a time period is given by the foundational formula .
Here, stands for the potential difference, is the constant current, and is the elapsed time.
Step 3: Detailed Explanation:
The given values extracted from the problem statement are:
Constant Current .
Potential difference .
Time duration .
Substitute these explicit values directly into the heating formula:
To express this large standard value in a more concise form like kilojoules (kJ), simply divide by 1000:
Step 4: Final Answer:
The total heat developed in the conductor is .