Calculate the power of the sunlight incident on the magnifying glass.
The radius is $1.5\,\text{mm}$. Determine the intensity of the light on area $A$.
Show that the waves have wavelength $8.1 \times 10^{-8}\,\text{m}$.
State the region of the electromagnetic spectrum to which these waves belong.
The beam from the laser now passes through a diffraction grating with $2400$ lines per millimetre. A detector sensitive to the waves emitted by the laser is moved through an arc of $180^\circ$ to locate the maxima produced by the waves passing through the grating, as shown in Fig. 5.2. Calculate the number of maxima detected as the detector moves through $180^\circ$ along the line shown in Fig. 5.2. Show your working.
The laser is now replaced with one that emits electromagnetic waves with a wavelength of $300\,\text{nm}$. Explain, without calculation, what happens to the number of maxima now detected. Assume that the detector is also sensitive to this wavelength of electromagnetic waves.
Calculate the number of maxima detected as the detector moves through $180^{\circ}$ along the line shown in Fig. 5.2. Show your working.
The laser is now replaced with one that emits electromagnetic waves with a wavelength of $300\,\text{nm}$. Explain, without calculation, how the number of maxima detected changes. Assume that the detector is also sensitive to electromagnetic waves of this wavelength.