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2 years ago

Calculate the light intensity 1.45 m from a light bulb that radiates 100 W equally in all directions.

Physics

1 answer:

ivanzaharov [21]2 years ago

5 0

Answer:

I = 3.785 W/m²

Explanation:

given,

distance from the light, r = 1.45 m

Power of bulb = 100 W

The area is that of a sphere with a radius equal to the distance from the light bulb.

The formula for the area of a sphere of radius 1.45 meters is:

A = 4 π r²

A = 4 x π x 1.45²

A = 26.42 m²

Intensity of the light is equal to

$I = \dfrac{P}{A}$

$I = \dfrac{100}{26.42}$

I = 3.785 W/m²

Intensity of the light at 1.45 m is equal to I = 3.785 W/m²

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An emf is induced in a conducting loop of wire 1.22 m long as its shape is changed from square to circular. Find the average mag

Afina-wow [57]

Answer:

The induced emf in the loop is $7.35\times 10^{-4}\ V$

Explanation:

Given that,

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The induced emf is given by :

$\epsilon=\dfrac{\d\phi}{dt}\\\\\epsilon=\dfrac{\d(BA)}{dt}\\\\\epsilon=B\dfrac{A'-A}{t}\\\\\epsilon=0.125 \times \dfrac{0.118-0.0930}{4.25}\\\\\epsilon=7.35\times 10^{-4}\ V$

So, the induced emf in the loop is $7.35\times 10^{-4}\ V$

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Answer:

for what?

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