Measure the power of the small bulb 1. What is the power of the small bulb marked with "2.5V 0.3A"________ W. To make it shine normally, it must be grounded______ V in the circuit 2. If a small bulb marked with "2.5V 0.3A" is connected to a 2V circuit and the measured current passing through it is 0.25A, then the rated power of the small bulb is_________ W. What is the actual power_________ W. 3. The brightness of the small bulb depends on () A. Voltage B. current C. actual power D. rated power

Measure the power of the small bulb 1. What is the power of the small bulb marked with "2.5V 0.3A"________ W. To make it shine normally, it must be grounded______ V in the circuit 2. If a small bulb marked with "2.5V 0.3A" is connected to a 2V circuit and the measured current passing through it is 0.25A, then the rated power of the small bulb is_________ W. What is the actual power_________ W. 3. The brightness of the small bulb depends on () A. Voltage B. current C. actual power D. rated power

0.75 2.5
0.75 0.5
C
(supplement: P = UI, i.e. power = voltage * current)

Is the actual power smaller than the rated power when the electric bulb is used for a long time?

P=I2RT
As the temperature increases, the resistance increases and the current decreases
But the current decreases in square
So the actual power is smaller

The larger the power of the small bulb, the brighter or darker the bulb?

There is a certain error in your question. Do you mean the rated power or the actual power of the small bulb? The brightness of the bulb depends on the actual power. The bigger the light, the brighter. It is the actual power that is connected to the circuit. The actual power with the higher rated power is not necessarily large, which should be calculated

Physics problems about mechanical power
Question: use fixed pulley and movable pulley to lift a and B objects of the same quality at the same speed to the same height, regardless of the friction in the rope, and the weight g of movable pulley is less than the weight g of B object, then its mechanical efficiency is a () B
Greater than or less than?

Power P = f · V
P a = mg · V
P = (mg / 2 + G / 2) · V
G is that the weight of the moving pulley is less than that of the object
If V in the two formulas is reduced to Mg (mg / 2 + G / 2), because g 〈 mg, so g / 2 〈 mg / 2
On the whole, the latter is less than the former
I hope you can understand it