Question

The advertised size of a television is the length of the diagonal of the rectangular viewing screen. For a
television advertised as 42-inch, if the ratio of the lengths of the sides of the viewing screen is 16 to 9,
approximately what is the area, in square inches, of the viewing screen?​

Answer 1

Step-by-step explanation:

Answer:-

Time period is 2.16 × 10⁻¹⁵ [Option.B]

Explanation:-

We have :-

→ Wavelength of red light = 6500 Å

= 6.5 × 10⁻⁷ m

→ Velocity of light = 3 × 10⁸ m/s

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Firstly let's calculate the frequency of the red light. We know that :-

ν = c/λ

⇒ ν = [3×10⁸]/[6.5×10⁻⁷]

⇒ ν = 0.46 × 10¹⁵

⇒ ν = 4.6 × 10¹⁴ Hz

Now :-

T = 1/ν

⇒ T = 1/[4.6 × 10¹⁴]

⇒ T = 0.216 × 10⁻¹⁴

⇒ T = 2.16 × 10⁻¹⁵ second