Question

Для вимірювання сили струму 5 А використовують амперметр, опір якого 2 Ом і розрахований для вимірювання струму до 100 мА. Визначити довжину мідного дроту площею поперечного перерізу 1,6×10^-6 м^2, який потрібно звити у котушку і приєднати паралельно амперметру для здійснення вимірювання. Питомий опір міді 1,68×10^-8 Ом×м.​

Answer 1

Відповідь:

Пояснення:

тримай розрахунок і пояснення на 2 листках, читай уважно, щось буде не зрозуміло, питай.  Опір, який розраховується для амперметрів, коли треба заміряти великий струм, а прилада такого не має, називається шунт. Як правило, усі шунти розраховуються і виготовляються індивідуально під те , чи інше вимірювання. Ми розрахували шунт для прилада на 100мА(0,1А) , а нам треба заміряти струм до 5А

Answer 2

To determine the length of the copper wire needed to be wound into a coil and connected in parallel to the ammeter for measuring a current of 5 A, we can use Ohm's Law and the formula for resistance.

Given Information:

- Current (I) = 5 A - Resistance of the ammeter (R) = 2 Ω - Maximum current measurement of the ammeter (I_max) = 100 mA = 0.1 A - Cross-sectional area of the copper wire (A) = 1.6 × 10^-6 m^2 - Specific resistance of copper (ρ) = 1.68 × 10^-8 Ω·m

Calculating the Total Resistance:

The total resistance in the circuit can be calculated by adding the resistance of the ammeter (2 Ω) to the resistance of the copper wire.

Total resistance (R_total) = Resistance of ammeter (R) + Resistance of copper wire

Calculating the Resistance of the Copper Wire:

The resistance of the copper wire can be calculated using the formula:

Resistance (R_wire) = (ρ × length) / A

Where: - ρ is the specific resistance of copper (1.68 × 10^-8 Ω·m) - length is the length of the copper wire - A is the cross-sectional area of the copper wire (1.6 × 10^-6 m^2)

Solving for the Length of the Copper Wire:

To solve for the length of the copper wire, we rearrange the formula for resistance:

length = (R_wire × A) / ρ

Substituting the given values:

length = (R_total - R) × A / ρ

Now we can calculate the length of the copper wire.

Calculation:

1. Calculate the total resistance: R_total = R + R_wire

2. Calculate the resistance of the copper wire: R_wire = (ρ × length) / A

3. Substitute the values into the formula for length: length = (R_total - R) × A / ρ

Let's calculate the length of the copper wire using the given values.

Step 1: Calculate the total resistance: R_total = 2 Ω + R_wire

Step 2: Calculate the resistance of the copper wire: R_wire = (1.68 × 10^-8 Ω·m × length) / (1.6 × 10^-6 m^2)

Step 3: Calculate the length of the copper wire: length = ((2 Ω + R_wire) × 1.6 × 10^-6 m^2) / (1.68 × 10^-8 Ω·m)

Now, let's calculate the length using the given values.

Step 1: Calculate the total resistance: R_total = 2 Ω + ((1.68 × 10^-8 Ω·m × length) / (1.6 × 10^-6 m^2))

Step 2: Calculate the length of the copper wire: length = ((2 Ω + ((1.68 × 10^-8 Ω·m × length) / (1.6 × 10^-6 m^2))) × 1.6 × 10^-6 m^2) / (1.68 × 10^-8 Ω·m)

To solve this equation, we can simplify it by multiplying both sides by (1.68 × 10^-8 Ω·m):

(1.68 × 10^-8 Ω·m) × length = (2 Ω + ((1.68 × 10^-8 Ω·m × length) / (1.6 × 10^-6 m^2))) × 1.6 × 10^-6 m^2

Simplifying further:

(1.68 × 10^-8 Ω·m) × length = (2 Ω × 1.6 × 10^-6 m^2) + (1.68 × 10^-8 Ω·m × length)

Now, we can solve for the length of the copper wire.

(1.68 × 10^-8 Ω·m - 1.68 × 10^-8 Ω·m) × length = (2 Ω × 1.6 × 10^-6 m^2)

0 × length = (2 Ω × 1.6 × 10^-6 m^2)

0 = (3.2 × 10^-6 Ω·m^2)

Since the equation results in 0 = 3.2 × 10^-6 Ω·m^2, there seems to be an error in the given values or calculations. Please double-check the values and calculations provided.

Please note that the specific resistance of copper (ρ) and the cross-sectional area of the copper wire (A) are typically used to calculate the resistance of the wire, not the length. The length of the wire is usually determined by other factors, such as the desired resistance or the physical constraints of the circuit.