21. Which one of the following ceramic composite has high melting temperature?

(a) Fibre glass

(b) Borosilicate

(c) Glass-ceramic

(d) Fused silica

Answer: (d)

22. Consider the following data regarding saturation magnetization and flux density for Nickel:

Answer: (c)

23. Which one of the following ferromagnetic material has the high critical temperature?

(a) Lead

(b) Tungsten

(c) Titanium

(d) Tin

Answer: (a)

24. Which one of the following is not a hard magnetic material?

(a) Tungsten steel

(b) Cobalt steel

(c) Barium ferrite

(d) Commercial iron

Answer: (d)

25. Consider the following properties for high temperature structural material:

1. Superior Oxidation Resistance

2. Superior Creep Resistance

3. High Hardness

4. Good Mechanical Strength

Which one of the following materials is having the potential to satisfy the above properties?

(a) Silicon carbide

(b) Ceramic

(c) Zirconia

(d) Alumina

Answer: (a)

26. In order to make optimum method for certain set of nano-structure patterns, materials and volume requirements which of the following steps of processes are involved?

1. Interference Lithography

2. Electron-Beam Lithography

3. Nano-Patterned Replication

(a) 1, 2 and 3

(b) 1 and 2 only

(c) 1 and 3 only

(d) 2 and 3 only

Answer: (a)

27. If a low pass filter has an input S/N of 20 and the input voltage is 3 mV then the noise voltage will be:

(a) 0.77 mV

(b) 0.67 mV

(c) 0.57 mV

(d) 0.47 mV

Answer: (b)

28. Consider the following set of independent current measurements:

10.03𝐴 , 10.10 𝐴, 10.11 𝐴, and 10.08 𝐴

The average range of error will be:

(a) ± 0.04 𝐴

(b) ± 0.03 𝐴

(c) ± 0.02 𝐴

(d) ± 0.05 𝐴

Answer: (a)

29. Electromagnetic damping is because of:

1. Friction produced owing to motion of coil in the air surrounding it

2. The induced effects when the coil moves in the magnetic field and closed path is provided for current to flow

3. Dissipation of energy of rotation

(a) 1 only

(b) 2 only

(c) 3 only

(d) 1, 2 and 3

Answer: (b)

30. A mild steel torsion bar of 30 𝑚𝑚 diameter is used for measurement of a torque of 100 Nm. If the shear modulus of mild steel is 80 GN/metre square, the angle of twist will be nearly:

Answer: (d)