Question

8 класс физика. 1. Электрические лампы мощностью 40 Вт и 80 Вт рассчитаны на одно и тоже напряжение. Какая из этих ламп обладает меньшим сопротивлением? Помогите пожалуйста!!!

Answer 1

Дано P1=40 Вт    P2=80 ВТ

P2/P1= U^2/R2  /  U^2/R1=R1/R2=2

сопротивление более мощной лампы меньше в 2 раза

Answer 2

У лампочки в 40 Ватт,меньшее сопротивление

Answer 3

Electrical Bulb Resistance Calculation

To determine which of the two bulbs, 40W or 80W, has a lower resistance, we can use the formula:

Power (P) = Voltage (V) × Current (I)

The resistance (R) of a device can be calculated using the formula:

Resistance (R) = Voltage (V) / Current (I)

Given that both bulbs are designed for the same voltage, we can compare their resistances based on their power ratings.

Calculation for 40W Bulb:

Using the formula P = V × I, we can rearrange it to find the current: I = P / V

For the 40W bulb: I = 40W / V

Calculation for 80W Bulb:

For the 80W bulb: I = 80W / V

Comparing the two currents will help us determine which bulb has a lower resistance.

Let's calculate the current for both bulbs and compare their resistances.

Current Calculation:

The current for the 40W bulb is 40W / V. The current for the 80W bulb is 80W / V.

Conclusion:

Based on the calculations, the bulb with a lower power (40W) will have a higher resistance compared to the bulb with higher power (80W). This is because the lower power bulb will draw less current at the same voltage, resulting in higher resistance.

Therefore, the 40W bulb has a higher resistance compared to the 80W bulb.