Subelement B: Electrical Math— Topic 10: Ohm’s Law-2
Question 3-10B4
Element 3 (GROL)In Figure 3B1, what is the voltage drop across R1?
Explanation
Figure 3B1 typically depicts a series circuit with a 12-volt DC power source connected to two resistors: R1 and R2.
1. **Identify Component Values:** From Figure 3B1, the voltage source is 12 volts, R1 is 5 ohms, and R2 is 7 ohms.
2. **Calculate Total Resistance (Rt):** In a series circuit, the total resistance is the sum of individual resistances.
Rt = R1 + R2 = 5 ohms + 7 ohms = 12 ohms.
3. **Calculate Total Circuit Current (I):** Using Ohm's Law (I = V/R), the total current flowing through the circuit is:
I = 12 volts / 12 ohms = 1 ampere.
In a series circuit, the current is the same through every component.
4. **Calculate Voltage Drop Across R1 (V_R1):** Using Ohm's Law (V = I * R), the voltage drop across R1 is:
V_R1 = 1 ampere * 5 ohms = 5 volts.
Therefore, the voltage drop across R1 is 5 volts.
Options A, B, and D are incorrect because they do not reflect the correct application of Ohm's Law based on the component values in Figure 3B1. For example, 7 volts would be the voltage drop across R2 (1A * 7 ohms).
Related Questions
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