SSRAO

Explanation:
The formula for Brinell Hardness Number (BHN) is given by: BHN = P / [(pi * D / 2) * (D - sqrt(D^2 - d^2))]
Where:
P = Load applied = 3000 kg
D = Diameter of the indenter = 10 mm
d = Diameter of the indentation = 4 mm

Substituting the values:
BHN = 3000 / [(pi * 10 / 2) * (10 - sqrt(10^2 - 4^2))]
BHN = 3000 / [5 * pi * (10 - sqrt(100 - 16))]
BHN = 3000 / [5 * pi * (10 - sqrt(84))]
BHN = 3000 / [5 * pi * (10 - 9.1651)]
BHN = 3000 / [5 * pi * 0.8348]
BHN = 3000 / 13.114 = 228.75 ~ 229.
Hence, the correct option is A.

Explanation:
Eddy Current Testing (ECT) operates on the principle of electromagnetic induction. When an alternating current flows through a coil placed near a conducting material, a varying magnetic field is created, inducing eddy currents in the material. Variations in the electrical conductivity or magnetic permeability of the test object, or the presence of any discontinuities, will alter the eddy current flow and change the phase and amplitude of the measured response. Thus, it relies on Faraday's Law. Options A, B, and D rely on sound waves, capillary action, and X-rays/gamma rays respectively.

Explanation:
The elastic component of strain is estimated from Hooke's law as εe = σ/E. Using consistent units, σ = 320 MPa and E = 200 GPa = 200,000 MPa. Thus εe = 320/200,000 = 0.0016. This is the elastic strain component; total strain at yielding may also include plastic strain.

Explanation:
The correct mapping is 1-Q (Charpy impact test measures impact toughness), 2-R (Jominy end-quench test evaluates steel hardenability), 3-P (Rockwell test measures hardness), and 4-S (cupping/Erichsen test assesses sheet-metal formability). Therefore, the correct sequence is 1-Q, 2-R, 3-P, 4-S.

Explanation:
The Vickers hardness test uses a square-based pyramid diamond indenter. The angle between the opposite faces of this square pyramid indenter is precisely 136 degrees. This angle was selected to approximate the ideal spherical indent geometry from Brinell testing when the indentation diameter is 0.375 times the ball diameter.

Explanation:
Radiographic testing uses X-rays or gamma rays and differences in attenuation to reveal internal volumetric discontinuities such as porosity and inclusions. Its suitability for thick steel sections depends on radiation energy, section thickness, access, and the required sensitivity. Liquid penetrant testing detects surface-breaking flaws, magnetic-particle testing detects surface and near-surface flaws in ferromagnetic materials, and visual inspection cannot reveal internal defects.

Explanation:
The net ligament height beneath the 2 mm notch is 10 − 2 = 8 mm. Net area = 10 mm × 8 mm = 80 mm² = 0.8 cm². Absorbed energy per unit net area = 40 J / 0.8 cm² = 50 J/cm². Strictly, Charpy results are usually reported as absorbed impact energy (J); energy per area is a derived quantity and should be labelled as such.

Explanation:
Piezoelectric transducers expand or contract when an alternating voltage is applied, generating high-frequency mechanical vibration (ultrasonic sound waves). Conversely, when returning acoustic echo waves stress the crystal mechanically, it outputs an electric signal. This bidirectional conversion is key to pulse-echo ultrasonic flaw detection.