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asambeis [7]
3 years ago
9

A 60-W light bulb radiates electromagnetic waves uniformly in all directions. At a distance of 1.0 mm from the bulb, the light i

ntensity is Io, the average energy density of the waves is u0, and the rms electric and magnetic field values are Eo and Bo, respectively.
Required:
a. What is the light intensity?
b. What is the average energy density of the waves?
c. What is the rms magnetic field value?
Physics
1 answer:
slega [8]3 years ago
4 0

Answer:

The appropriate solution is:

(a) \frac{1}{4}(I_o)

(b) \frac{1}{4} (u_o)

(c) \frac{1}{2}B_o

Explanation:

According to the question, the value is:

Power of bulb,

= 60 W

Distance,

= 1.0 mm

Now,

(a)

⇒  \frac{I}{I_o} =\frac{r_o_2}{r_2}

On applying cross-multiplication, we get

⇒  I=I_o\times \frac{1_2}{2^2}

⇒     =I_o\times \frac{1}{4}

⇒     =\frac{1}{4} (I_o)

(b)

As we know,

⇒ \frac{u}{u_o} =\frac{I}{I_o}

By putting the values, we get

⇒ u=\frac{1}{4}(u_o)

(c)

⇒ \frac{B^2}{B_o^2} =\frac{u}{u_o}

         =\frac{I}{I_o}

⇒ B=B_o\times \sqrt{\frac{1}{4} }

⇒     =\frac{1}{2}(B_o)

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