IB Physics/Digital Technology Option

C.2.5 Define quantum efficiency of a pixel.
Quantum efficiency is the ratio of the number of photoelectrons emitted to the number of photons incident on the pixel.

C.4.1 State that any area is divided into a number of cells (each with its own base station) to which is allocated a range of frequencies.
Every area is divided into a number of cells (each with its own base station) to which is allocated a range of frequencies

C.4.3 Discuss the use of mobile phones in multimedia communication.
•	Vocal communication •	Text communication (SMS, chatting etc.) •	Communication through social networks on mobile phone (facebook, twitter etc.) •	Communication can be one-to-one or one-to-many

Advantages: •	Time efficient •	Cost efficient •	Best way to reach lots of people •	Easy

Disadvantages: •	No information is private •	Lack of control of information •	Less real life communication

C.4.4 Discuss the moral, ethical, economic, environmental and international issues arising from the use of mobile phones.
Moral / Ethical – Firstly, less human interaction in between adolescents as they are now able to lie at home and speak through their phones. Secondly, employees are distracted by their mobile phones when at their workplace. Economic- Not every one are able to afford mobile phones. International- It is now faster and simpler to communicate with people around the world. Environmental- Disposing of 15m phones each year just in the UK. Mobile phones contain cadmium, rhodium, palladium, beryllium and lead solder, which are all highly toxic.