select the correct answer.\na series circuit has two 5.0 - ohm resistors and a power source of 9.0 volts…

select the correct answer.\na series circuit has two 5.0 - ohm resistors and a power source of 9.0 volts. how will the current be affected and what will it be if another resistor (with a resistance of 7.5 ohms) is added to the circuit?\na. increase; 0.51 amps\nb. increase; 0.72 amps\nc. increase; 3.6 amps\nd. decrease; 0.51 amps\ne. decrease; 0.72 amps

select the correct answer.\na series circuit has two 5.0 - ohm resistors and a power source of 9.0 volts. how will the current be affected and what will it be if another resistor (with a resistance of 7.5 ohms) is added to the circuit?\na. increase; 0.51 amps\nb. increase; 0.72 amps\nc. increase; 3.6 amps\nd. decrease; 0.51 amps\ne. decrease; 0.72 amps

Answer

Answer:

E. decrease; 0.51 amps

Explanation:

Step1: Calculate initial total resistance

The initial circuit has two 5.0 - ohm resistors in series. The total initial resistance $R_{1}$ is $R_{1}=5 + 5=10$ ohms.

Step2: Calculate initial current

Using Ohm's law $I=\frac{V}{R}$, where $V = 9.0$ volts and $R = R_{1}=10$ ohms. So the initial current $I_{1}=\frac{9}{10}=0.9$ amps.

Step3: Calculate new total resistance

A 7.5 - ohm resistor is added in series. The new total resistance $R_{2}=10 + 7.5=17.5$ ohms.

Step4: Calculate new current

Using Ohm's law again with $V = 9.0$ volts and $R = R_{2}=17.5$ ohms. So the new current $I_{2}=\frac{9}{17.5}\approx0.51$ amps. Since $I_{2}<I_{1}$, the current decreases to 0.51 amps.