IGCSE Computer Science 39/23 EXAM WITH ANSWERS [APPROVED]

IGCSE Computer Science 39/23 EXAM WITH ANSWERS [APPROVED] binary numbers are used in *Ans* computer systems conversion from denary to binary and from binary to denary uses *Ans* place values (128,64,32,16,8,4,2,1) memory size of a computer is measured in terms of the number of *Ans* bytes 1 kilobyte is *Ans* 2 to the 10 bytes 1 megabyte is *Ans* 2 to 20 bytes 1 kilobyte according to manufactures *Ans* 1000 bytes unit symbols *Ans* kilobyte-kB megabyte, gigabyte,tera byte is- CAPITAL thenB Each memory size increases by *Ans* 1000 so mega byte has a 1000 kilobytes so thus a 1000000 bytes and a giga byte has a 1000 mByte Why choose Hex *Ans* Quicker to read, easier/quicker to write in hex, less likely to make errors copying so easier to debug Letters in Hex *Ans* A=10 B=11 C=12 D=13 E=14 F=15 MAC addresses *Ans* Media Access Control address. 12-bit identification number unique for each device. Unique number that identifies a device, manufacturer ID and serial number of device, address is allocated by manufacturer Defining colours in HTML *Ans* Uses hexadecimal when representing colours, combinations of hex codes are used to represent different colours #FF 00 00 = primary red #00 FF 00 = primary green #00 00 FF = primary blue sound, music, pictures, video, text and number are *Ans* stored in different formats Data Transmission *Ans* Transferring binary data from sender to receive