## Screw Gauge Viva Questions and Answers

**Screw Gauge Viva Questions and Answers**

*(ii) What is meant by pitch of a screw gauge?*

*(iii) The pitch of a screw is 1 mm and the number of divisions on the head scale is 100. What is the least count?*

*(iv) What is zero error of a screw gauge?*

*(v) If the zero of the head scale is 5 divisions above the line of graduation of the pitch scale when the gap is closed, what is the zero error? What is the zero correction? Least count of the vernier = 0.01 mm*

*(vi) If the zero of the head scale is 5 divisions below the line of graduation of the pitch scale when the gap is closed, what is the zero error and correction? Least count = 0.01 mm*

*(vii) Why do we take a number of observations for the diameter of a wire?*

*(viii) Why do you stop rotating the screw as soon as the ratchet begins to turn between the fingers?*

*(ix) Aim of Screw Gauge Experiment*

Ans: To find

(a) the diameter of a wire and

(b) thickness of an irregular glass plate using screw gauge and find their volumes.

*(x) Theory of Screw Gauge Experiment*

Ans: Dimension measured = P.S.R + fraction = P.S.R + (H.S.R x L.C);

where P. S . R = Pitch Scale Reading,

H.S.R = Head Scale Reading

and L.C = Least count of the screw gauge

Volume of the wire = πr^{2}l;
where r = radius of the wire and l = length of the wire

*(xi) How to find the pitch of the screw?*

Ans: Pitch = Distance moved/Number of rotations

*(xii) How to find the least count of the screw gauge?*

Ans: The least count of the screw is the distance moved by it when it is rotated through one division of the head scale.

Least count = Pitch/No: of divisions on the head scale.

*(xiii) How to find the zero correction?*

Ans: The screw is turned till the tip touches the stud. If the zero division does not coincide with zero of the pitch scale, then it is zero error. So a correction has to be applied. If it is not screwed, there is no zero correction. If it is over screwed, the zero correction is positive (+3 divisions). If it is under screwed, the zero correction is negative (-2 divisions).

*(xiv) How to find the diameter and volume of the wire?*

Ans: Diameter of the wire = P.S.R + fraction = P.S.R+ (corrected H.S.R. x L.C)

Volume (V) of the wire is calculated using the equation, V = πr^{2}l

*(xv) How to find the thickness and volume of the glass plate?*

Ans: The given glass plate is griped between the tip of the screw and the stud. The P.S.R and the H.S.R are noted as before. The thickness of the glass plate is

t = P.S.R + (corrected H.S.R) x LC

The glass plate is placed over a graph paper and its outline is traced on the graph paper. The area A of the glass plate is taken from the graph paper. The volume of the glass plate is calculated from the equation.

V = A x t

## Vernier Caliper Viva Questions and Answers

**Vernier Caliper Viva Questions and Answers**

**(ii) What is meant by least count of a vernier calipers?**

**(iii) The least count of a vernier is 0.001 cm. What is the order upto which it can measure length accurately?**

**(iv) What part of the vernier calipers is the vernier scale?**

**(v) Which is the instrument you will use to measure the internal and external diameter of a tube?**

**(vi) Apparatus of Vernier Calipers**Ans: The vernier calipers, the given cylinder and the metallic rectangular block. The vernier calipers consists of a main scale and a small subscale called vernier scale. The main scale is usually graduated in mm. The vernier scale is a sub-scale which can slide along the main scale and can be fixed at any position with the help of a screw. Usually there will be 10 divisions on the vernier scale which are equivalent to 9 mm on the main scale. The main scale and the vernier scale are provided with jaws at their ends. When the jaws are in contact, the zero of the vernier coincides with the zero of the main scale.

**(vii) Theory of Vernier Calipers**Ans: When a body is gripped between the jaws, the main scale reading (M.S.R) is the reading on the main scale just before the zero mark of the vernier scale and the vernier scale reading (V.S.R) is the number of the vernier division which coincides with some division of the main scale.

^{2}l;

^{2}h

*(viii) Procedure* of Vernier Calipers

**To find the least count (LC) of the vernier calipers**

**(a) To measure the dimensions of the cylinder**

^{2}l

**(b) To find the volume of the given rectangular block of known mass by measuring its dimensions with the vernier calipers and hence to find its density.**

**(c) To find the internal radius (r), depth (h) and volume (V) of the calorimeter.**

^{2}h

## Microwave Engineering Viva Questions and Answers

*1. Give the range of frequency Band of Microwave?*

*2. Why the Micro wave got the name as microwaves?*

*3. Discuss in detail about Electromagnetic Frequency Spectrum?*

*4. List the major advantages of Microwaves?*

*5. List the major applications of Microwaves?*

*6. Give the frequency band of Infrared Rays (IR)?*

*7. Discuss the band of visible Light?*^{14}to 8 × 10

^{14 }cycles per second, or hertz (Hz) and wavelengths ranges from 740 nanometers (nm) or 2.9 × 10

^{−5}inches, to 380 nm (1.5 × 10

^{−5}inches).

*8. Mention the band of X Rays?*^{16}Hz to 3×10

^{19}Hz).

*9. What is the band of gamma Rays?*^{20}- 10

^{24}and the wavelength is in the range < 10 - 12 m

*10. Define Phase velocity and Group velocity?**The velocity having a wave packet that travels is referred as group velocity. Whereas, the velocity having the phase of a wave that travels is referred as phase velocity.*

*11. The standard frequency used in Microwave Oven for heating is?*

*12. Give the speed of Electromagnetic waves in free space?*^{8}m/s.

*13. Explain about the propagation of EM waves?*

*14. What is Faraday's law?**Faraday's law is defined as a current that would be induced in a conductor which is exposed to a varying magnetic field*

*15. Define Gauss law?**Gauss's law is defined as the net flux of an electric field that is closed in an enclosed surface is directly proportional to the enclosed electric charge.*

*16. Define Ampere's law?**the magnetic field caused by an electric current would be proportional to the size of electric current having a constant of proportionality corresponding to the permeability of free space”.*

*17. Define TEM wave?*

*18. What you understand by Transverse Electric (TE) wave?*

*19. What is mean by Transverse magnetic (TM) waves?*

*20. What you understand about EM wave?*

*21. Discuss about the need of Transmission line?*

*22. Discuss about the types of transmission lines?*

*23. What is single stub matching?*

*24. List the main advantages of microwave integrated circuits (MIC)?*

*25. Discuss about reflection coefficient?*

*26. Discuss about the different types of losses in transmission lines?*## EDC Lab Viva Questions with Answers

##
**Electronic Devices and Circuits Lab Viva Questions with Answers**

_{o}(e

^{(V/ηVT})-1),

_{o}is the Reverse saturation current, and the value of η=1 for germanium, and 2 for silicon.

_{z}) is less than 6V (breakdown voltage), V

_{z}is inversely proportional to temperature.

_{z}is directly proportional to temperature, if the the breakdown voltage is greater than 6V