# What is the power of this bulb

• hms.tech
In summary, the question asks to calculate the brightness of the bulbs (g and h) in a new configuration using the equation P = V^(2)/R. The voltage across "g" will be 2V and its resistance is the same as in the reference attachment, making "g" brighter than normal. The voltage across "h" is V, resulting in "h" being of normal brightness. It is acceptable to rely on one of the two formulas (P = V^(2)/R or P = R*I^(2)) as long as it is applied correctly.
hms.tech

## Homework Statement

See attachment
The question asks to calculate the brightness of the bulbs(g and h) in this new configuration.

## Homework Equations

Since brightness $\propto$ Power

P= $V^{2}$/R
P= $I^{2}$R
E.M.F of One cell : V

## The Attempt at a Solution

I used the equation P = V^(2)/R

Since the Voltage across "g" will be 2V and its Resistance is exactly the same as in the reference Attachment, "g" will be brighter than normal.
Similarly, since the Voltage across "h" is going to be V, "h" must be of normal brightness.

I am not sure if my answers make sense since if we apply the 2nd formula : P=R*I^2
we would get a different set of results .

Is it O.K to just rely on one of the two formulas and deduce the final answer based on say P=V^(2)/R ? Would the answers be authentic ?

#### Attachments

• Capture.PNG
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hms.tech said:
I am not sure if my answers make sense since if we apply the 2nd formula : P=R*I^2
we would get a different set of results .
Not if you do it correctly. Pls post your working.

## 1. What is the power of this bulb?

The power of a bulb is the amount of energy it uses per unit time, measured in watts. It determines how bright the bulb will be and how much electricity it will consume.

## 2. How do you determine the power of a bulb?

The power of a bulb can be determined by dividing the energy it uses (measured in joules) by the time it takes to use that energy (measured in seconds). This calculation results in watts, the unit of power.

## 3. Is the power of a bulb the same as its brightness?

No, the power of a bulb and its brightness are different. The power of a bulb determines how much energy it consumes, while the brightness is a measure of how much light it produces.

## 4. Does the type of bulb affect its power?

Yes, the type of bulb can affect its power. Different types of bulbs, such as incandescent, LED, and fluorescent, have different power ratings and consume different amounts of energy.

## 5. Why is it important to know the power of a bulb?

Knowing the power of a bulb is important because it can help you determine its energy efficiency and how much it will cost to operate. It can also help you compare different types of bulbs to find the most suitable option for your needs.

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