Question

В.16.Плоский воздушный конденсатор заряжен до разности потенциалов 150 В. После отключения от источника напряжения расстояние между пластинами конденсатора было увеличено в пять раз. Определить разность потенциалов на обкладках конденсатора после их раздвижения.

Answer 1

кондеасатор отключили, значит заряд постоянный

C1 = q/U1 = e e0 S/d1  (1)

C2 = q/U2 = e e0 S/d2  (2)

делим (2) на (1)

q/U2  /  q/U1  = e e0 S/d2 / e e0 S/d1

U1/U2  = d1/d2       d2/d1 = 5

U2 = U1 *d2/d1 = 150*5 =750 B

 

Answer 2

Calculation of Potential Difference after Increasing the Distance between the Plates

To determine the potential difference on the plates of the capacitor after increasing the distance between them, we can use the formula for the capacitance of a parallel-plate capacitor:

C = ε₀ * (A / d)

Where: - C is the capacitance of the capacitor, - ε₀ is the permittivity of free space (approximately 8.85 x 10^-12 F/m), - A is the area of the plates, - d is the distance between the plates.

Given that the potential difference before increasing the distance is 150 V, and the distance between the plates is increased by a factor of 5, we can use the formula to find the new potential difference.

Let's assume the initial distance between the plates is d₀ and the new distance is d. We can set up the following equation:

C₀ * V₀ = C * V

Where: - C₀ is the initial capacitance, - V₀ is the initial potential difference, - C is the new capacitance, - V is the new potential difference.

Since the capacitance is inversely proportional to the distance between the plates, we can write:

C₀ / d₀ = C / d

Rearranging the equation, we get:

C₀ * d = C * d₀

Now, substituting the formula for capacitance, we have:

(ε₀ * (A / d₀)) * d = (ε₀ * (A / d)) * d₀

Simplifying the equation, we get:

d₀ / d = A / A

Since the area of the plates remains the same, we can cancel out the terms:

d₀ / d = 1

Therefore, the ratio of the initial distance to the new distance is 1. This means that the potential difference remains the same after increasing the distance between the plates.

Hence, the potential difference on the plates of the capacitor after their separation remains 150 V.