Practice Pakistan's most useful MCQs for competitive exams

The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K) ?

• (A)  T
• (B)  1/T
• (C)  T2
• (D)  1/T2

Answer

Submitted By :Ali Uppal

Common salt is produced from sea water in India generally by the ________________ method?

• (A)  Freeze drying
• (B)  Solar evaporation
• (C)  Electrolytic
• (D)  None of these

Answer

Submitted By :Ali Uppal

Which of the following phenomenon/ phenomena is/are diffusion controlled ?

• (A)  Dislocation climb
• (B)  Cross-slip
• (C)  Twinning
• (D)  Recrystallisation

Answer

Submitted By :Ali Uppal

Air/fuel ratio on molar (volume) basis for combustion of methane with theoretical quantity of air with be________________?

• (A)  9.5 : 1
• (B)  12.5 : 1
• (C)  15.5 : 1
• (D)  18.5 : 1

Answer

Submitted By :Ali Uppal

Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frother ?

• (A)  Cresylic acid
• (B)  Xanthaies
• (C)  Pine oil
• (D)  All A,

Answer

Submitted By :Ali Uppal

While the thermosetting polymers are amorphous in nature, the thermoplastic polymers are either amorphous or crystalline. The crystalline polymers are characterized by the ?

• (A)  Low impact strength
• (B)  High flexibility
• (C)  Better finish and surface appearance
• (D)  High plastic deformation

Answer

Submitted By :Ali Uppal

______________ the exhaust gas is an indication of the incomplete combustion of fuel?

• (A)  Low temperature of
• (B)  High temperature of
• (C)  High % of CO in
• (D)  High % of CO2 in

Answer

Submitted By :Ali Uppal

Which of the following terminology is used for the temperature at which new grains are formed in a metal ?

• (A)  Eutectic temperature
• (B)  Lower critical temperature
• (C)  Recrystallisation temperature
• (D)  Upper critical temperature

Answer

Submitted By :Ali Uppal

In ________________ process, there is an increase in entropy with no degradation of energy ?

• (A)  Isothermal expansion
• (B)  Isochoric heat addition
• (C)  Polytropic expansion
• (D)  Isobaric heat addition

Answer

Submitted By :Ali Uppal

Triple point of water is__________________?

• (A)  0.01 °C
• (B)  492°R
• (C)  0°K
• (D)  -273°C

Answer

Submitted By :Ali Uppal