Two lightbulbs are each connected to a voltage of 120 V. One has a power of 25 W, the other 100 W. (a) Which lightbulb has the higher resistance? (b) Which lightbulb carries more current?

(a) The 25 W bulb

(b) The 100 W bulb

Explanation:

(a)

Using,

P = V²/R Equation 1

Where P = Power, V = Voltage, R = resistance.

make R the subject of the equation

R = V²/P Equation 2

For the 25 W bulb,

Given: P = 25 W, V = 120 V

Substitute into equation 2

R = 120²/25

R = 576 Ω

For the 100 W bulb,

Given: P = 100 W, V = 120 V

Substitute into equation 2

R = 120²/100

R = 14400/100

R = 144 Ω

Hence the the 25 W bulb has the highest resistance.

(b)

Using,

P = VI Equation 3,

Where I = current

Make I the subject of the equation

I = P/V Equation 4

For the 25 W bulb,

Given: P = 25 W, V = 120 V

Substitute into equation 4

I = 25/120

I = 0.208 A.

For the 100 W bulb,

Given: P = 100 W, V = 120 V

Substitute into equation 4

I = 100/120

I = 0.833 A.

Hence the 100 W bulb carries more current.

c.is a substance that requires a small amount of energy per gram to raise its temperature; has strong cohesive forces between molecules.

explanation:

a colorless, transparent, odorless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.