What is the SI unit of Planck’s constant?
Correct answer B. J s
Explanation
From E = hf, h = E/f, so its unit is J divided by s⁻¹, which is J s. Its value is about 6.63 × 10⁻³⁴ J s.
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More Dawn of Modern Physics questions
See allAn X-ray photon has a wavelength of 0.10 nm. What is its energy in keV (h = 6.63 × 10⁻³⁴ J s, c = 3.0 × 10⁸ m/s, e = 1.6 × 10⁻¹⁹ C)?
Correct answer C. 12.4 keV
What is the threshold wavelength for a metal whose work function is 2.0 eV (h = 6.63 × 10⁻³⁴ J s, c = 3.0 × 10⁸ m/s, e = 1.6 × 10⁻¹⁹ C)?
Correct answer C. 622 nm
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What is the momentum of a photon of wavelength 663 nm (h = 6.63 × 10⁻³⁴ J s)?
Correct answer C. 1.0 × 10⁻²⁷ kg m/s
A photon has an energy of 3.0 eV. What is its wavelength (h = 6.63 × 10⁻³⁴ J s, c = 3.0 × 10⁸ m/s, e = 1.6 × 10⁻¹⁹ C)?
Correct answer D. 414 nm
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