Question

ЭДС источника тока 10В. Когда к нему подключили сопротивление 20Ом,сила тока у цепи составила 4А. Определите ток короткого замыкания.

Answer 1

1) По закону Ома для полной цепи:I=ЭДС/(R+r), где I-сила тока, R-сопротивление цепи, r-внутреннее сопротивление. При коротком замыкании R->0, следовательно I=ЭДС/r
2) Найдем внутреннее сопротивление: r=(ЭДС-IR)/I 
r=(10-4*2)/4=0,5(Ом)
3)При коротком замыкании: I=ЭДС/r=10/0,5=20 (А)
Ответ: 20 Ампер

Answer 2

Calculation of Short Circuit Current

To determine the short circuit current, we need to use Ohm's Law, which states that the current flowing through a circuit is equal to the voltage divided by the resistance:

I = V / R

In this case, the electromotive force (EMF) or voltage of the current source is given as 10V, and the resistance in the circuit is 20Ω. The current flowing through the circuit is given as 4A.

Using Ohm's Law, we can rearrange the formula to solve for the voltage:

V = I * R

Substituting the given values, we have:

V = 4A * 20Ω = 80V

Therefore, the voltage across the 20Ω resistor is 80V.

Now, to calculate the short circuit current, we assume that the resistance in the circuit becomes zero. In this case, the voltage across the short circuit is also zero. Therefore, the short circuit current can be calculated by dividing the voltage (which is zero) by the resistance (which is zero):

I_short_circuit = V_short_circuit / R_short_circuit = 0 / 0

However, dividing by zero is undefined, and we cannot determine the exact value of the short circuit current using this method.

In summary, when the resistance in the circuit becomes zero (short circuit), the current flowing through the circuit cannot be determined using Ohm's Law. The short circuit current is typically very high, limited only by the internal resistance of the current source and the wiring impedance.

Please note that the calculation above assumes an ideal current source with no internal resistance. In practical scenarios, the short circuit current may be limited by the internal resistance of the current source or other factors.

Let me know if there's anything else I can help you with!