Why binary language termed as machine language.Why required.

Q11. Why is binary language often termed as machine language? Why is machine language required?

Ans. A computer (the machine) operates on electricity. Thus, it can understand only electricity signals that are just two-ON and OFF or high voltage and low voltage. Thus it needs a language that uses just two unique symbols to represent these two states of electricity. Therefore, a computer works on the machine language. The binary language is often termed as machine language as it fulfills the condition of using two unique symbols to represent two states of electricity.

Difference between RAM and ROM.

Q18. What is the difference between RAM and ROM?

Ans. RAM refers to Random Access Memory where both read and write operation take place. But the RAM is a volatile memory, its content a are lost when power is turned off.

ROM refers to Read Only Memory where read operation take place.ROM is a non-volatile memory.

Both RAM and ROM are part of the primary memory.

Working of a Dot-Matrix Printer.

Q17. Explain working of a dot-matrix printer.

Ans. In the dot-matrix printer (dmp), an arrangement of tiny hammers strikes to produce the desired characters. Each hammer prints a small dot in the paper.

The printing head of dmp’s contains a vertical array of pins. As the head moves across the paper, selected pins “fire” against an inked ribbon to form a pattern of dots on the paper. Using this feature, a dmp can even pictures, graphs etc. In the figure, the capital letters are formed by 5-dot rows and 7-dot columns (i.e., a row having 5 dots and a column having 7 dots). Such a pattern is called a 5 x 7 matrix. But, the printing head of a dmp consists of 9 pins where bottom 2 pins are used for descender (lower portions) of small letters like y, j etc.

Difference between OCR and OMR.

Q14. What is the difference between OCR and OMR?

Ans. An Optical Character Reader (OCR) is used to read characters of special type font that are printed on conventional paper with conventional ink.

On the other hand, an Optical Mark Reader (OMR) is used to transcribe marks that are marked with a dark pencil or ink on a special preprinted formĀ  (e.g., answer sheet of the multiple choice question paper where a choice of answer can be reflected by shading the appropriate box).

An OCR also comprised of a logical system that attempts to determine which of he possible characters is being examined.