Top 1000+ Solved Non Destructive Testing and Evaluation MCQ Questions Answer
Q. What causes a leakage field in a steel bar?
a. A crack
b. Reversal of the magnetic field
c. Paint on the surface
d. All of the above
Q. An indication is a defect under which of the following conditions?
a. If it is greater than 3.8 cm (1.5 inches) long
b. If it exceeds the limits of a standard or specification
c. If it is deep
d. Under all of the above indications
Q. Paint will not affect the detection of a crack if:
a. The paint is thick and the defect is subsurface
b. The paint is thin and the crack is parallel to the direction of flux lines
c. The crack is sharp and the paint is thin
d. All of the above
Q. A magnetic particle indication is sharp and very fine; this suggests that thediscontinuity is:
a. Subsurface seam
b. A shallow, tight surface crack
c. Porosity
d. A deep crack
Q. Among the following, the best type of current for the detection of fatigue cracks is:
a. Half-wave direct current
b. Alternating current
c. Direct current
d. Half-wave alternating current
Q. Continuous magnetization provides the most sensitivity because:
a. The magnetic particles are present while the part is being magnetized
b. The magnetic field is greatest while the magnetizing current is on
c. All of the above
d. Neither of the above
Q. The sensitivity of magnetic particle testing is greatest when the discontinuity is:
a. Parallel to the direction of the magnetic flux lines
b. Perpendicular to the flow of the magnetizing current
c. Perpendicular to the direction of the magnetic flux
d. Perpendicular to the line between prods
Q. To provide reliability and reproducibility in magnetic particle testing, writtenprocedures should include:
a. Location of the coil and current for each magnetization
b. Requirements for ammeter calibration
c. Type and concentration of the particles
d. All of the above
Q. The magnetic particles are noticed to bunch in some fillet areas and stand on end onthe edge of a part being magnetized. These observations indicate that the:
a. Particle concentration is too low
b. Flux density is excessive
c. Flux density is too low
d. Magnetizing current should be changed form AC to DC
Q. Flux density is a measure of the number of magnetic flux lines perpendicular to an area of cross-section. If a discontinuity is in the plane of the unit area, the strongest magnetic article indication will be formed when the discontinuity is:
a. Inclined at 45º to the flux lines
b. Parallel to the flux lines
c. 90º to the flux lines
d. 135º to the flux lines
Q. Prods are being used to magnetize a weld area. When dry powder is dusted on the surface, it is observed that there is no mobility of the particles. What is the most probable reason for this observation?
a. The magnetizing current is not high enough
b. The flux density is too low
c. DC is being used
d. All of the above are possible reasons
Q. The current from portable high amperage units can be applied to the object using:
a. Prods
b. Cable coils
c. Pre-wrapped coils
d. All of the above
Q. How can parts be tested to determine if they have been adequately demagnetized?
a. By bringing a suspended paper clip near the middle of the part
b. By using a small horseshoe permanent magnet
c. By using a small magnetometer held at a corner of the part
d. By sprinkling some magnetic particles on the part
Q. The statement ‘magnetic particle testing can be applied to plated and painted parts’.
a. May be true depending upon the thickness of the coating
b. May be true if flux densities are increased to compensate for the coating thickness
c. Is true only for circular circumstances
d. Both (a) and (b)
Q. A group of indications, some sharp and some broad and fuzzy, were found on an area of a small forging. Demagnetization and re-inspection eliminated these indications. What was the probable cause?
a. Forging lap
b. Magnetic writing
c. Change in permeability
d. Subsurface variation