Finding unknown resistance and current in series and parallel circuits

[mustang]

Problem 7.
A(n) 5.0 ohm resistor is connected in series with another resistor and a 6.0 V battery. The current in the circuit is 0.64A.
Calculate the value of the unkonwn resistance. Answer in ohms.
Note: I don't how to slove this problem.

Problem 11.
A 6.0V battery is connected to four resitors, 8.1ohm, 6.5ohm, 4.0ohm, 6.1ohm. Calculate the current in the 6.1 ohm resistor. Answer in A.

Problem 13.
A(n) 3.2 ohm resistor, a(n) 7.0 ohm resistor, and a(n) 14.1 ohm resistor are connected in parallel across a 24.0 V battery.
What is the current in the 3.2 ohm resistor? Answer in A.

 

[chroot]

Start with problem 7. When you wire resistors in series, their resistances add. Thus the total resistance in the circuit is 5 + R ohms, where R is the unknown resistance. Ohm's law indicates the total current in the circuit must be 6.0 V / (5 + R) ohms = 0.64 A.

Solve for R.

- Warren

 

[M98Ranger]

To solve these series resistor problems, we can use Ohm's Law which states that the current (I) in a circuit is equal to the voltage (V) divided by the resistance (R), or I = V/R. We can also use the formula for total resistance in a series circuit, which is Rtotal = R1 + R2 + R3 + ..., where R1, R2, R3, etc. are the individual resistances in the circuit.

Problem 7:
In this problem, we are given the value of one resistor (5.0 ohms), the voltage of the battery (6.0 V), and the current in the circuit (0.64 A). We can use Ohm's Law to solve for the unknown resistance:
R = V/I = 6.0 V/0.64 A = 9.375 ohms.
Therefore, the unknown resistance is 9.375 ohms.

Problem 11:
In this problem, we are given the voltage of the battery (6.0 V) and the values of four resistors (8.1 ohms, 6.5 ohms, 4.0 ohms, and 6.1 ohms). To find the current in the 6.1 ohm resistor, we first need to find the total resistance of the circuit:
Rtotal = 8.1 ohms + 6.5 ohms + 4.0 ohms + 6.1 ohms = 24.7 ohms.
Now, we can use Ohm's Law to solve for the current in the 6.1 ohm resistor:
I = V/R = 6.0 V/24.7 ohms = 0.243 A.
Therefore, the current in the 6.1 ohm resistor is 0.243 A.

Problem 13:
In this problem, we are given the values of three resistors (3.2 ohms, 7.0 ohms, and 14.1 ohms), the voltage of the battery (24.0 V), and the fact that they are connected in parallel. To find the current in the 3.2 ohm resistor, we can use the formula for total resistance in a parallel circuit:
1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ...
1/Rtotal = 1/3.2 oh