Physics : Electronics , Computers

 PHYSICS – 5

ELECTRONICS

Band Theory of Solids : 

1) Rubber is __________

Ans : Insulator

2) A very poor conductor of electricity is called an _______

Ans : Insulator 

3) Metals are ______ of electricity

Ans : good conductors

4) The energy gap of conductor is ______

Ans : zero

5) The conductivity of a semiconductor depends on its _________

Ans : temperature

6) The absence of an electron is the valence band of a semiconductor is called a _______

Ans : hole

7) Hole is a _______ charge carrier of current 

Ans : positive

8) Both holes and electrons are the _______ in a semiconductor

Ans : charge carriers

9) Semi – conductors are classified in to how many types?

Ans : Two

10) Semiconductors are classified into two type. They are_____

Ans : 1) Intrinsic   2) Extrinsic semiconductors

11) Insulators are _____ conductors of electricity.

Ans : poor

12) Insulators are poor conductors of electricity because the energy gap is relating large  and the concentration of ____ is small

Ans : electrons

13) Substances that conduct electricity are known as ______

Ans : electric conductors

14) The flow of ______ constitutes an electric current

Ans : electron

15) An example for p-type semi-conductor is _____

Ans : Silicon with Aluminium as impurity

16) The number of free electrons are more in _________

Ans : copper

17) The energy gap is highest in the case of _______

Ans : insulator

18) When temperature of a semi-conductor is raised, the energy gap _______

Ans: decreases

19) By whom  the charge carried in a semi-conductor 

Ans : electrons and holes

INTRINSIC AND EXTRINSIC SEMI-CONDUCTORS:

1) Purre semiconductors are called _____ semi-conductors

Ans: intrinsic

2) In n-type semiconductor the majority carriers are ________

Ans: electrons

3) To make silicon a p-type semiconductor, the impurity to be doped is ______

Ans : aluminium

4) Introducing impurities in very small  quantities into a material is called ______

Ans : doping

5) ______ semi conductors are the semiconductors doped with desired impurity.

Ans : Extrinsic

6) Depending on the type of impurity extrinsic semi-conductors are how many types?

Ans : Two types

1) p-type

2) n-type

7) Trivalent impurities are called ________

Ans :acceptors

8) Pentavalent  impurities are called ________

Ans : donors

9) Phosphorous  is a _________ impurity

Ans : pentavelent

10) Aluminium is a _____ impurity

Ans : trivalent

11) p-type and n-type semi-conductors are electrically______

Ans : neutral

12) An example for intrinsic conductor is ________

Ans : germanium

13) A semiconductor acts as an insulator at _______

Ans : 0° K

14) The charge carriers in a semiconductor are ________

Ans : electrons and holes

JUNCTION DIOIDE-PROPERTIES AND USES:

1) A Diode offers ______ resistance under reverse bias condition

Ans : high

2) In rectifier circuits _____ are used.

Ans: diodes

3) p-type semi-conductor has excess number of _______

Ans : holes

4) n-type semi – conductor has excess number of _______

Ans : electrons

5) LED means ______

Ans : Light Emitting Diode

6) What is Diode?

Ans : It is a rectifier

7) ______ are used in digital clock and digital calculators

Ans: LEDs

8) LEDs _____ on supply of current

Ans: glrow

TRANSISOTRS – PROPERTIES AND USES:

1) The three terminals of a transistors are called ___________ and ________

Ans : Emitter,     base,     collector

2) Transistors are used in ________ which produce signals of different frequencies.

Ans : oscillators

3) The transistor was invented by _________

Ans : J.Bardeen, W.H.Brattain and William Shockley

4) The transistor is a small semi-conductor device which is at the _____ of the modern day electronic appliances.

Ans : heart

5) A transistor is a combination of two _____ joined back to back.

Ans : diodes

6) A transistor consists of 3 terminals namely, emitter, base and _______

Ans : collector

7) I.C. stands for ________

Ans : Integrated Circuits

8) Integrated circuits are called ____

Ans : Chips

9) Transistor act as _________

Ans : amplifier

10) Chips are important in the ______

Ans: micro electronic systems

RADIO AND TELEVISION – BASIC PRINCIPLES OF WORKING : 

1) r.f. stands for _________

Ans : Radio frequency

2) The process of fixing messages to r.f. carrier waves is called __________

Ans : modulation

3) A.M. is the abbreviation for ___________

Ans : Amplitude Modulation

4) At home the r.f. modulated carrier wave is received by _________

Ans : aerial or antenna

5) Electromagnetic waves in radio frequency range are used for _____ and ______ communication.

Ans : Radio  and      R.V.

6) FM is the abbreviation for _________

Ans : Frequency Modulation

7) The process of extracting information from the modulated r.f. carrier waves is called ________

Ans : demodulation

8) ________ produces electromagnetic waves of different frequencies

Ans : Induction coil

9) For radio communication the range of carrier frequency is from   about ______

Ans : 300 KHz to 30 MHz

10) For television communication frequency range of carriers is from about ________

Ans : 30 MHz to 300 MHz

11)  Modulated waves are sent  into space by a ________

Ans : transmitting antenna

12) The three states in radio  or TV communication are ________

Ans : 1) production of messages  2) transmission  3) detection

13) _______ modulate r.f. waves carrying messages

Ans : Transmitters

14) ______ is a process of dividing an image on the screen into a large number of very small squares formed by sets of horizontal and vertical straight lines.

Ans : Scanning

15) Tuning circuits are also called as _______

Ans : Channel selector

16) TV is known as ______

Ans : Kinescope

17) _______ is a camera consisting of a cathode ray beam and  a photo cell.

Ans : Iconoscope

18) Now a days ______ is used for scanning prupose.

Ans : Iconoscope

19) Induction coil produces ______ waves of different frequencies

Ans : Electromagnetic (EM)

20) Radio waves travel through _______ over a long distances and can be used as carriers of messages

Ans : space

21) Messages are converted into ______ signals

Ans : electrical

22) Electrical signals re superimposed on _______

Of suitable high (radio) frerquency

Ans : electromagnetic waves

23) The frequencies used in TV communications are in the range of 30 MHz to _____

Ans : 300 MHJz

24) The name of the camera which consists of a cathode ray beam and photocell is _______

Ans : Iconoscope

COMPUTER – BASIC PRINCIPLES OF WORKING : 

1) IC means________

Ans : Integrated Circuit

2) Key board is an _______

Ans :Input device

3) A set of _______ is called a programme

Ans : instructions

4) A CPU consists of ______________

Ans : Control Unit (CU), Memory, Arithmetic Logic Unit(ALU)

5) A ______ language is independent of machine

Ans : high level

6) ASSEMBLER is a ______ language

Ans : machine

7) A semi conductor consisting of combinations of large number o f diodes and transistors  in it is called ___________ 

Ans : Integrated Circuit or Chip

8) A _______ is a combination of ICs

Ans : Microprocessor

 9) Data and instructions are supplied to the computer through an _______

Ans : Input device

10) CPU means ________

Ans : Central Processing Unit 

11) Printer is an _______

Ans : Output device

12) _______ is the heart of the computer

Ans : CPU

13) The number system, consists of only two digits 0 and 1 is called ______ system

Ans : binary

14) A binary digit either 1 or 0 is called a ______

Ans : bit

15) In  BCD code the first four bits are  called Zero bits and the remaining 

        four bits are called _____ bits

Ans : numeric

16) ___________language is internal language of the computer

Ans: Machine

17) Machine language depends on ______ of a computer

Ans : Hardware

18) BASIC is a ________ language

Ans : high level

19) A  Compiler translates ________________________________

Ans : a high level programme to machine language instructions

20) Computer programme can be written in ___________ language

Ans : high level

21) All the physical components like CPU input and output devices put together are called _____ of the computer

Ans : Hardware

22) The electronic circuits are called _________

Ans : logic circuits

23) A combination of ICs is called a __________

Ans : microprocessor

24) Data and instructions are supplied through an ________

Ans : input devices  (like Keyboard, mouse, Scanner, Camera, Joy Stick etc.)

25) The microprocessor (Chip)  also consists of a second component called _______

Ans : Memory

26) the last component of the microprocessor (Chip) is called ________

Ans : Arithmetic Logic Unit (ALU)

27) The Printer or a visible screen is called ______

Ans : Monitor

28) The output device is _________

Ans : Monitor

29) The combination of CU, Memo and ALU is _________

Ans : CPU or Central Processing Unit

30) A computer uses a number system different from our ______ system

Ans: decimal

31) The number system consists of two digits i.e., zero and ________, in computers

And : one 

32) The digit zero or one is called _________

Ans : bit

33) In BCD , the 4 bits are called ____________

Ans : Zonal bits

34) The function of a Compiler is to _____________

Ans : translate the high level  language instructions into machine language

35) Byte is formed by __________

Ans : a group of 8 bits

36) A set of instructions is called a __________

Ans : programme