An edge dislocation is present in α-Fe. Atomic diameter of iron atom is 0.25 nm and its shear modulus is 70 GPa. Modulus of the Burgers vector (in nm) is

The Burgers vector b is the vector which defines the magnitude and direction of slip. For a pure edge dislocation, the Burgers vector is perpendicular to the dislocation line, while for a pure screw dislocation, the Burgers vector is parallel to the dislocation line.

A

True

B

False

What is the difference between the angle of Burgers vector and dislocation line in edge dislocation and screw dislocation?

A

-90 degrees

B

0 degrees

C

45 degrees

D

90 degrees

Shear stress required to bend a dislocation of radius R and burger vector b is P. What will be shear stress needed to turn a dislocation of radius 2R and burger’s vector 2b to bend the dislocation?

A

P

B

2P

C

4P

D

16P

The interaction of screw dislocation and edge dislocation produces ______ on the edge dislocation and _______ on the screw dislocation.

A

a jog with an edge orientation, a kink with an edge orientation

B

a kink with an edge orientation, a jog with an edge orientation

C

a jog with a screw orientation, a kink with a screw orientation

D

a kink with a screw orientation, a jog with a screw orientation

What is the resolved shear stress, when dislocation density in metal is equal to 1012m-2? Given that shear stress needed in the absence of dislocation is 500MPa. Numerical constant is 0.3 and shear modulus is 80GPa, burger vector is 1 nm.

A

500MPa

B

550MPa

C

600 MPa

D

524 MPa

A glass reinforced polymer composite comprises of 35 volume % glass fiber and 65 volume % of polymer resin. The elastic moduli of glass and polymer resin are respectively 70 GPa and 3 GPa. The elastic modulus of the composite (in GPa) under iso-strain state is

A

4.51

B

25.45

C

26.45

D

27.45

Calculate the shear modulus for steel in GPa, if given that young modulus is 215 GPa and possion’s ratio is 0.33?

A

40 GPa

B

50 GPa

C

80 GPa

D

100 GPa

An elliptical dislocation loop is gliding on plane ABCD of a single crystal of BCC material as shown in the following figure. It is gliding along the burger vector 'b'. Identify the correct statement.
Physics of Metals in Metallurgy mcq question image

Physics of Metals in Metallurgy mcq question image

P. Plane ABCD belongs to the family of (110).
Q. Burger vector 'b' belong to direction.
R. Dislocation has the edge character at point x and the screw character at point z.
S. Dislocation has the screw character at point x

A

P, Q

B

Q, R

C

P, R

D

P, S

Shear modulus of copper is 45 GPa. Lattice parameter of copper is 3.61°A. The magnitude of burgers vector in copper is . . . . . . . . °A.

A

2.54

B

2.39

C

2.20

D

2.18

The angle between the line vector and the burgers vector of an edge dislocation is

A

0 degree

B

90 degrees

C

120 degrees

D

180 degrees

An edge dislocation is present in α-Fe. Atomic diameter of iron atom is 0.25 nm and its shear modulus is 70 GPa. Modulus of the Burgers vector (in nm) is

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