Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. The frequency (ν) and wave number of this yellow light would be, respectively:

1. 517 × 10¹⁴ s^–1 , 172 × 10⁶ m^–1

2. 6.17 × 10¹⁴ s^–1 , 1.72 × 10⁶ m^–1

3. 4.17 × 10¹⁴ s^–1 , 2.72 × 10⁶ m^–1

4. 5.17 × 10¹⁴ s^–1 , 1.72 × 10⁶ m^–1

A photon detector receives a total energy of \(3.15 \times 10^{-18}\) J from radiation with a wavelength of 600 nm. How many photons are received by the detector?

$1.$ ${10}^2$
$2.$ $10$
$3.$ $50$
$4.$ $20$

A 25-watt bulb emits monochromatic yellow light with a wave length of 0.57µm. The rate of emission of quanta per second would be :

1. 7.17 × 10^–19 s^–1

2. 4.13 × 10¹⁶ s^–1

3 . 7.17 × 10¹⁹ s^–1

4 . 1.26 × 10²⁰ s^–1
${\mathrm{}}^{}$