Question
13.6. Rajah 13.6 menunjukkan sebatang penunjuk laser menghasilkan pancaran yang mempunyai kuasa 1.5mW dan panjang gelombang 6.5 \times 10^{-13} m.
Diagram 13.6 shows a laser pointer produces a beam of power 1.5mW and wavelength of 6.5 \times 10^{-13} ma) Zarah-zarah pancaran laser dikenali sebagai foton.
The particle of laser beam known as photon.
(i) Apakah maksud foton?
What is meant by photon?
[1 markah](ii) Berikan satu ciri foton.
Give one characterisitc of photon.
[1 markah](b) Diberi h=6.33 \times 10^{-34} Js, c= 3 \times 10^8 ms^{-1} , hitung
Given h=6.33 \times 10^{-34} Js, c= 3 \times 10^8 ms^{-1}, calculate
(i) tenaga foton
the energy of a photon.
[2 markah]
Answer
Hi Farhaini,
I believe that your working is entirely correct and it’s the question that gave the incorrect information.
To get the mark scheme answer,
Planck’s constant should be 6.63 \times 10^{-34} Js and wavelength given should be 6.5 \times 10^{-7} m instead of 6.5 \times 10^{-13} m ! An EM wave with a wavelength of magnitude 10^{-12} m or smaller is already in the gamma ray spectrum, a gamma-ray laser hasn’t been invented up to this day hahaha 
when we talk about laser beam it’s usually in the visible light spectrum or infrared spectrum.
Hope this helps! 
Wahhh you are so smart any tips so that I can be smart too? 
I’m not smart haha, I just finished A levels and still remember some stuff from this topic actually but from the way you ask questions and from your working I can tell that you’re a smart student too! 
Practicing more state papers and making sure you understand the questions and concepts is a great way to prepare for SPM (even though some of them have a lot of errors haha 
) All the best Farhaini! I believe that you will do well for your SPM! ^w^
Wahh Thank you very muchh!! I will try my best
