Question

При силе тока 0,5 А вольтметр показывает 3 В, а при силе тока 1 А - 2,5 В. Найти ЭДС и внутреннее сопротивление источника.

Answer 1

Внутреннее сопротивление 7 ом
а ЭДС 9,5

Answer 2

Given Information

- Current (I) = 0.5 A - Voltage (V) = 3 V - Current (I) = 1 A - Voltage (V) = 2.5 V

Finding the EMF and Internal Resistance of the Source

To find the electromotive force (EMF) and internal resistance of the source, we can use Ohm's Law and the equation for the total voltage in a circuit.

According to Ohm's Law, the voltage (V) across a resistor is equal to the current (I) multiplied by the resistance (R). Mathematically, this can be represented as V = I * R.

In this case, the voltage measured by the voltmeter is the total voltage (V) in the circuit. The voltmeter measures the potential difference across the source and the internal resistance combined.

Let's denote the EMF of the source as E and the internal resistance as r.

Using the given information, we can set up the following equations:

Equation 1: V = E - I * r (when I = 0.5 A and V = 3 V) Equation 2: V = E - I * r (when I = 1 A and V = 2.5 V)

We can solve these equations simultaneously to find the values of E and r.

Substituting the values from the first equation: 3 = E - 0.5 * r

Substituting the values from the second equation: 2.5 = E - 1 * r

Now we have a system of two equations with two unknowns (E and r). We can solve this system of equations to find the values of E and r.

Subtracting the second equation from the first equation: 3 - 2.5 = E - 0.5 * r - (E - r) 0.5 = 0.5 * r r = 1

Substituting the value of r into the first equation: 3 = E - 0.5 * 1 3 = E - 0.5 E = 3.5

Therefore, the electromotive force (EMF) of the source is 3.5 V and the internal resistance is 1 ohm.

Conclusion

The electromotive force (EMF) of the source is 3.5 V and the internal resistance is 1 ohm.