State True or False. (10 Marks)
a) Transistor replaced vacuum tubes in the second generation computers.
b) Windows allows handling multiple files.
c) We needn’t require including an extension while writing a file name.
d) Merging cell means to break a cell into more sub cells.
e) MARK I was the first fully operational electronic computer.
f) Java is considered as low level language.
g) Denis Ritchie invented C++ language
h) Copy Paste means moving a file from one place to another.
i) We can delete a table along with its contents.
j) Wild card characters are used to save a file into a computer.
3) Write the full for of the following. (5 Marks)
a) COBOL b) ALL c) UNIVAC d) AI e) BASIC
4) Name the following. (5 Marks)
a) Two extensions of video files.
b) Two types of vertical alignments.
c) Two object oriented programming languages.
d) Inventor of C Language and Java Language.
e) Two categories of files.
Section – B (Answer any five questions) (50 Marks)
5) Answer the following questions. (5+5)
a) Give two advantages and limitations of High Level Languages.
b) Enlist three features of the second generation of computers.
Answers
Answer:
thermionic valve uses the phenomenon of thermionic emission of electrons from a hot cathode and is used for a number of fundamental electronic functions such as signal amplification and current rectification. Non-thermionic types, such as a vacuum phototube however, achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light intensities. In both types, the electrons are accelerated from the cathode to the anode by the electric field in the tube.
The simplest vacuum tube, the diode, invented in 1904 by John Ambrose Fleming, contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through the device—from the cathode to the anode. Adding one or more control grids within the tube allows the current between the cathode and anode to be controlled by the voltage on the grids.[5]
These devices became a key component of electronic circuits for the first half of the twentieth century. They were crucial to the development of radio, television, radar, sound recording and reproduction, long-distance telephone networks, and analog and early digital computers. Although some applications had used earlier technologies such as the spark gap transmitter for radio or mechanical computers for computing, it was the invention of the thermionic vacuum tube that made these technologies widespread and practical, and created the discipline of electronics.[6]
In the 1940s, the invention of semiconductor devices made it possible to produce solid-state devices, which are smaller, more efficient, reliable, durable, safer, and more economical than thermionic tubes. Beginning in the mid-1960s, thermionic tubes were being replaced by the transistor. However, the cathode-ray tube (CRT) remained the basis for television monitors and oscilloscopes until the early 21st century. Thermionic tubes are still used in some applications, such as the magnetron used in microwave ovens, certain high-frequency amplifiers, and amplifiers that audio enthusiasts prefer for their "warmer" tube sound.
Not all electronic circuit valves/electron tubes are vacuum tubes. Gas-filled tubes are similar devices, but containing a gas, typically at low pressure, which exploit phenomena related to electric discharge in gases, usually without a heater.