光的波動性

Compare the time taken for the following waves to travel a distance of $100$ m. $T_1$ Water waves with frequency $0.5$ Hz and wavelength $2$ m $T_2$ Sound waves travelling at $340\ \mathrm{m\,s^{-1}}$ $T_3$ Microwaves emitted by an artificial satellite The time taken in **descending** order is

In the figure, a laser speed gun is used to check for speeding. A car is approaching the speed gun. The speed gun emits a laser pulse. The speed gun receives the reflected pulse from the car after $3.6\times10^{-7}$ s. After $0.2$ s, the speed gun emits another laser pulse. The speed gun receives the reflected pulse from the car after $3.1\times10^{-7}$ s. What is the estimated speed of the car ? Given that speed of the laser pulse is $3\times10^{8}\ \mathrm{m\,s^{-1}}$.

Which of the following graphs showing the relationship among velocity ($v$), frequency ($f$) and wavelength ($\lambda$) of electromagnetic waves in vacuum is/are correct ?

Which of the following shows the correct order of the relative positions of five electromagnetic waves in the electromagnetic spectrum, in the order of decreasing wavelength ?

A ship is equipped with certain devices. Which device is **not** an application of electromagnetic waves ?

The photograph shows a digital video camera recorder. The recorder has a night-shot function of capturing images in the dark. Which of the following electromagnetic waves is employed by the recorder in capturing images in the dark ?

Scientists have discovered that ozone molecules in the earth's atmosphere are being destroyed. Which of the following electromagnetic waves is mainly responsible for causing hazard to human health as a result of the damaging of the ozone layer ?