Question

4 multiple choice 1 point
9 v
voltage drop across points 3 and 4?
0 volts
7 volts
18 volts
9 volts

Explanation:

Step1: Identify Circuit Type

The resistors \( R_1 \), \( R_2 \), \( R_3 \) are in parallel with the voltage source (9V). In a parallel circuit, the voltage across each branch (and across any two points connected by a wire, like 3 - 4) is equal to the source voltage? Wait, no—wait, points 3 and 4: look at the circuit. Points 1 - 2 - 3 - 4 are connected by a wire (no resistance), and 8 - 7 - 6 - 5 are connected by a wire. So the voltage between 3 and 4: since 3 is connected to 2 (which is at + side of battery) and 4 is also connected to 2? Wait, no, wait the wires: 1 - 2 - 3 - 4 are a single conductor (zero resistance), so points 1,2,3,4 are at the same potential (positive terminal of the battery, 9V relative to the negative terminal). Similarly, points 8,7,6,5 are at the same potential (negative terminal, 0V relative to positive). Wait, no—wait, the voltage across points 3 and 4: since 3 and 4 are connected by a wire (zero resistance), the voltage drop (potential difference) between them is \( V = IR \), but \( R = 0 \) (wire), so \( V = 0 \). Wait, but also, the resistors are in parallel, so each resistor has 9V across it, but points 3 and 4: let's see, point 3 is connected to the top of \( R_2 \), point 4 is connected to the top of \( R_3 \), but since 3 and 4 are connected by a wire (no resistor), the potential at 3 and 4 is the same. So the voltage drop (difference) between 3 and 4 is 0V.

Step2: Confirm with Parallel Circuit

In a parallel circuit, the voltage across each resistor is equal to the source voltage, but between two points connected by a short (wire, \( R = 0 \)), the voltage drop is \( V = I \times 0 = 0 \). So the voltage drop across 3 and 4 is 0V.

Answer:

0 Volts