Chemical Engineering Gate 2012 Questions with Answer

Ques 40 GATE 2012

Wanted Temporary, Part-time persons for the post of Field Interviewer to conduct personal interviews to collect and collate economic data. Requirements: High School-pass, must be available for Day, Evening and Saturday work. Transportation paid, expenses reimbursed. Which one of the following is the best inference from the above advertisement?

Ques 41 GATE 2012

Given the sequence of terms, AD CG FK JP, the next term is

Ques 42 GATE 2012

Which of the following assertions are CORRECT?
P: Adding 7 to each entry in a list adds 7 to the mean of the list
Q: Adding 7 to each entry in a list adds 7 to the standard deviation of the list
R: Doubling each entry in a list doubles the mean of the list
S: Doubling each entry in a list leaves the standard deviation of the list unchanged

Ques 43 GATE 2012

For heat transfer across a solid-fluid interface, which one of the following statements is NOT true when the Biot number is very small compared to 1?

Ques 44 GATE 2012

A solid sphere with an initial temperature T_i is immersed in a large thermal reservoir of temperature T_o. The sphere reaches a steady temperature after a certain time t₁. If the radius of the sphere is doubled, the time required to reach steady-state will be

Ques 45 GATE 2012

If the Nusselt number (Nu) for heat transfer in a pipe varies with Reynolds number (Re) as Nu∝Re^0.8, then for constant average velocity in the pipe, the heat transfer coefficient varies with the pipe diameter D as

Ques 46 GATE 2012

The one - dimensional unsteady state heat conduction equation in a hollow cylinder with a constant heat source q is (∂T/∂t)=(1/r)(∂/∂r)(r(∂T/∂r))+q. If A and B are arbitrary constants, then the steady state solution to the above equation is

Ques 47 GATE 2012

For the enclosure formed between two concentric spheres as shown below (R₂=2R₁), the fraction of radiation leaving the surface area A₂ that strikes itself is

Ques 48 GATE 2012

Heat is generated at a steady rate of 100 W due to resistance heating in a long wire (length =5 m, diameter =2 mm). This wire is wrapped with an insulation of thickness 1 mm that has a thermal conductivity of 0.1 W/m.K. The insulated wire is exposed to air at 30°C. The convective heat transfer between the wire and surrounding air is characterized by a heat transfer coefficient of 10 W/m².°C. The temperature (in °C) at the interface between the wire and the insulation is

Ques 49 GATE 2012

In a counter-flow double pipe heat exchanger, oil (m=2 kg/s C_p=2.1 kJ/kg.°C) is cooled from 90°C to 40°C by water (m=1 kg/s, C_p=4.2 kJ/kg.°C) which enters the inner tube at 10°C. The radius of the inner tube is 3 cm and its length is 5 m. Neglecting the wall resistance, the overall heat transfer coefficient based on the inner radius, in kW/m².K is

Ques 50 GATE 2012

In a 1-1 pass floating head type shell and tube heat exchanger, the tubes (od=25 mm; id=21 mm) are arranged in a square pitch. The tube pitch is 32 mm. The thermal conductivity of the shell side fluid is 0.19 W/m.K, and the Nusselt number is 200. The shell-side heat transfer coefficient (in W/m².K), rounded off to the nearest integer, is

Ques 51 GATE 2012

A thermometer initially at 100°C is dipped at t=0 into an oil bath, maintained at 150°C. If the recorded temperature is 130°C after 1 minute, then the time constant of thermometer (in min) is

Ques 52 GATE 2012

The Bode stability criterion is applicable when