Question

2 лампы рассчитаны на напряжение 120в и 220 вольт, имеют одинаковую мощность, по какой из них пойдет больший ток? ответ поясните

Answer 1

согласно формуле P=UI ток больше там,где напряжение меньше

поэтому ток будет больший в лампочке с напряжением 120 в

Answer 2

Background Information

To determine which lamp will draw a larger current, we need to consider the relationship between voltage, current, and power. The power consumed by an electrical device can be calculated using the formula: Power (P) = Voltage (V) x Current (I).

Given that both lamps have the same power rating and are designed for different voltages (120V and 220V), we can use this information to determine which lamp will draw a larger current.

Calculation

Since the power rating of both lamps is the same, we can assume that the power consumed by each lamp is equal. Let's denote the power as P.

For the lamp designed for 120V, the power consumed can be calculated as P = 120V x I1, where I1 is the current flowing through the lamp.

For the lamp designed for 220V, the power consumed can be calculated as P = 220V x I2, where I2 is the current flowing through the lamp.

Since the power consumed by both lamps is the same, we can equate the two equations:

120V x I1 = 220V x I2

To determine which lamp will draw a larger current, we need to compare the values of I1 and I2.

Solution

To solve the equation, we can rearrange it to solve for I1:

I1 = (220V x I2) / 120V

From the equation, we can see that the current flowing through the lamp designed for 120V (I1) is directly proportional to the current flowing through the lamp designed for 220V (I2). Since the voltage of the lamp designed for 220V is higher, the current flowing through it will be smaller compared to the lamp designed for 120V.

Therefore, the lamp designed for 120V will draw a larger current compared to the lamp designed for 220V.

Please note that this calculation assumes that the power rating of both lamps is the same and that the lamps are operating within their specified voltage range.

Conclusion

In summary, when two lamps have the same power rating but are designed for different voltages, the lamp designed for the lower voltage will draw a larger current. In this case, the lamp designed for 120V will draw a larger current compared to the lamp designed for 220V.