Temperature Measurement Multiple Choice Questions

Question 1

Identify the thermocouple type with the highest temperature limit from those listed here:

(A) Type J
(B) Type K
(C) Type S
(D) Type T
(E) Type E

Answer  : C

Question 2

The negative lead of a thermocouple is always colored:

(A) Blue
(B) Yellow
(C) Red
(D) White
(E) Black

Answer  : C

Question 3 

The most rugged temperature sensing element listed here is a/an:

(A) Thermocouple
(B) Orifice plate
(C) RTD
(D) Filled bulb
(E) Fire eye

Answer  : A

Question 4

Convert a temperature measurement of 250 deg C into Kelvin.

(A) 523.2 K
(B) -209.7 K
(C) 709.7 K
(D) -23.2 K
(E) 23.2 K

Answer  : A

Question 5

When the reference junction is the same temperature as the measurement junction in a thermocouple circuit, the output voltage (measured by the sensing instrument) is:

(A) Zero
(B) Reverse polarity
(C) Noisy
(D) AC instead of DC
(E) Unreliable

Answer  : A

Question 6

A “thermowell” is a:

(A) Heat sink
(B) Small vessel for holding liquids at high temperature
(C) Protective tube for a temperature sensing element
(D) Temperature sensing device
(E) Safety relief device for high pressure

Answer  : C

Question 7

Reference junction compensation is necessary in thermocouple-based temperature instruments because:

(A) Copper extension wire has a tendency to corrode
(B) Thermocouples are inherently nonlinear
(C) The reference junction generates a temperature-dependent voltage
(D) The junction’s electrical resistance varies with temperature
(E) Electrical noise may interfere with the measurement otherwise

Answer  : C

Question 8

Latent heat is:

(A) The heat required to raise the temperature of a substance
(B) The amount of heat energy present in ambient conditions
(C) The potential energy residing in a sample of unburnt fuel
(D) The heat released when a gas suddenly decreases pressure
(E) The heat required to make a substance change phase

Answer  : E

Question 9 

Thermocouple extension wire may be readily distinguished from regular thermocouple-grade wire by:

(A) Different metal types
(B) Outer sheath color
(C) Special markings on the wire’s insulation
(D) Thickness
(E) Flexibility (stranded instead of solid)

Answer  : B

Question 10

A type J thermocouple is made of the following metals:

(A) Aluminum and Tungsten
(B) Iron and Constantan
(C) Platinum and Platinum/Rhodium alloy
(D) Copper and Constantan
(E) Chromel and Alumel

Answer  : B

Credits : by Tony R. Kuphaldt