Math Problem Statement

. Two resistors are connected in parallel and a voltage of 200 Volts is applied to the terminals. The total current taken is 25A and the power dissipated in one of the resistor is 1500W. Determine the resistance of each element?

Solution

Given:

  • Two resistors R1R_1 and R2R_2 are connected in parallel.
  • The applied voltage across the parallel combination is V=200V = 200 V.
  • The total current drawn is Itotal=25I_{\text{total}} = 25 A.
  • The power dissipated by one of the resistors (let's assume R1R_1) is P1=1500P_1 = 1500 W.

Step 1: Find R1R_1

We can use the power formula to find R1R_1: P1=V2R1P_1 = \frac{V^2}{R_1} Rearranging for R1R_1: R1=V2P1=20021500=40000150026.67ΩR_1 = \frac{V^2}{P_1} = \frac{200^2}{1500} = \frac{40000}{1500} \approx 26.67 \, \Omega

Step 2: Find the current through R1R_1

Using Ohm's law, the current through R1R_1 is: I1=VR1=20026.677.5AI_1 = \frac{V}{R_1} = \frac{200}{26.67} \approx 7.5 \, \text{A}

Step 3: Find the current through R2R_2

The total current is the sum of the currents through R1R_1 and R2R_2: Itotal=I1+I2I_{\text{total}} = I_1 + I_2 25=7.5+I225 = 7.5 + I_2 Solving for I2I_2: I2=257.5=17.5AI_2 = 25 - 7.5 = 17.5 \, \text{A}

Step 4: Find R2R_2

Using Ohm's law for R2R_2: R2=VI2=20017.511.43ΩR_2 = \frac{V}{I_2} = \frac{200}{17.5} \approx 11.43 \, \Omega

Final Answer:

  • R126.67ΩR_1 \approx 26.67 \, \Omega
  • R211.43ΩR_2 \approx 11.43 \, \Omega

Would you like further details or have any questions?

Here are some related questions to consider:

  1. How is power dissipated in a resistor related to current and resistance?
  2. What would happen to the total current if the voltage increased to 300V?
  3. How would the problem change if the resistors were connected in series instead of parallel?
  4. How do you calculate the equivalent resistance of parallel resistors?
  5. What are the implications of using resistors with very different resistances in a parallel circuit?

Tip: In a parallel circuit, the voltage across each resistor is the same as the source voltage, but the current splits according to the resistances.

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Math Problem Analysis

Mathematical Concepts

Ohm's Law
Power in Electric Circuits
Parallel Circuits

Formulas

P = V^2 / R
I = V / R
I_total = I_1 + I_2

Theorems

Ohm's Law
Power Dissipation Formula

Suitable Grade Level

Grades 9-12