1224. In a totally irreversible isothermal expansion process for an ideal gas, ΔE = 0, ΔH = 0. Then ΔQ and ΔS will be
A. ΔQ = 0, ΔS=0
B. ΔQ = 0 , ΔS = +ve
C. ΔQ = 0, ΔS = -ve
D. ΔQ = +ve , ΔS= +ve
✅ The correct answer is option B.
1226. Metal cutting by oxy-acetylene flame is accomplished by the __________ of the metal.
A. Burning
B. Intensive oxidation
C. Evaporation
D. None of these
✅ The correct answer is option B.
1228. α-rays are
A. Negatively charged
B. Positively charged
C. Neutral
D. Same as X-rays
✅ The correct answer is option B.
1215. Photographic plates are coated with
A. Silver nitrate
B. Silver halide
C. Calcium silicate
D. Metallic silver
✅ The correct answer is option B.
1217. Galvanic corrosion
A. Occurs in a bimetal couple
B. Occurs in highly stressed metallic parts only
C. Is exemplified by caustic embrittlement of boiler tubes
D. Is also called dezincification
✅ The correct answer is option A.
1219. The behaviour of a metal specimen, which when plastically strained in tension reduces its yield stress in compression and vice versa; is termed as the
A. Work hardening
B. Bauschinger effect
C. Creeping effect
D. Stress recovery effect
✅ The correct answer is option B.
1221. Unit molar solution of __________ is the best conductor of electricity.
A. Sodium chloride
B. Acetic acid
C. Sulphuric acid
D. Sucrose
✅ The correct answer is option C.
1223. Basicity [%Cao + %MgO/% SiO₂) of the slag in Indian blast furnace is in the range of
A. 0.7-1.0
B. 1.1-1.4
C. 1.5 – 1.8
D. 2.0 – 2.5
✅ The correct answer is option B.
1225. A metal having a Poisson’s ratio = 0.3 is elastically deformed under uniaxial tension. If the longitudinal strain = 0.8, then the magnitude of thickness strain is
A. -0.8
B. 0.8
C. +0.08
D. -0.24
✅ The correct answer is option D.
1227. Cast iron compared to steel is better in
A. Ductility
B. Strength
C. Malleability
D. Fluidity & castability
✅ The correct answer is option D.