This set of Food Packaging Technology Quiz focuses on “Glass as Packaging Material”.
1. Glass is a super cooled liquid.
a) True
b) False
View Answer
Explanation: The given statement is true. Glass has been defined by the American Society for Testing and Materials (ASTM) as “an amorphous, inorganic product of fusion that has been cooled to a rigid condition without crystallizing”.
2. The main component of glass is _____
a) silica
b) quartz
c) sand
d) flint
View Answer
Explanation: The main component of glass is silica. The principal ingredient of glass is silica derived from sand, flint or quartz. Silica can be melted at very high temperatures (l723°C) to form fused silica glass which, because it has a very high melting point, is used for specialized applications including some laboratory glass.
3. The glass surface is subject to corrosion due to the presence of ______
a) magnesium
b) potassium
c) sodium
d) calcium
View Answer
Explanation: The glass surface is subject to corrosion due to the presence of sodium. The glass surface is subject to three forms of “corrosion”: etching, leaching and weathering, as a consequence of the sodium in glass being loosely combined in the silica matrix.
4. _______ is characterized by alkaline attack in glass.
a) Leaching
b) Etching
c) Scaling
d) Surface bloom
View Answer
Explanation: Etching is characterized by alkaline attack, which slowly destroys the silica network, releasing other glass components. It is a form of corrosion in glass.
5. What is the basic structural unit of silica in glass?
a) Tetrahedron
b) Octahedron
c) Square bipyramidal
d) Trigonal bipyramidal
View Answer
Explanation: The basic structural unit is the silicon oxygen tetrahedron in which a silicon atom is tetrahedrally coordinated to four surrounding oxygen atoms. This amorphous structure, without slip planes formed by crystal boundaries that might allow deformation, is responsible for the stiffness and brittleness of glass.
6. ________ is characterized by acid attack in glass.
a) Weathering
b) Scaling
c) Leaching
d) Surface bloom
View Answer
Explanation: Leaching is characterized by acid attack in which hydrogen ions exchange for alkali or other positively charged mobile ions. The remaining glass (principally silica) usually retains its normal integrity.
7. _______ mild form of weathering in glass.
a) Scaling
b) Surface bloom
c) Tempering
d) Leveling
View Answer
Explanation: A mild form of weathering is commonly known as surface bloom and may occur under extended storage conditions. To save the glass from surface bloom, fluorine gas is generally used.
8. ______ is the part of the bottle that holds the cap or closure.
a) Finish
b) Body
c) Fissure
d) Seal
View Answer
Explanation: Finish is the part of the bottle that holds the cap or closure, the glass surrounding the opening in the container. It includes thread and neck.
9. _______ of the container is the portion that is made in the body-mold.
a) Head
b) Shoulder
c) Cavity
d) Body
View Answer
Explanation: Body of the container is the portion that is made in the body-mold. Body lies between the finish and the bottom and is generally the largest part of the container. Shoulder is the part between base of neck and the body.
10. Silica is combined with _______ to increase hardness and durability in glass.
a) boron
b) alumina
c) lead
d) alkali flux
View Answer
Explanation: Silica is combined with alumina to increase hardness and durability in glass. Glass contains around 1.5%–2% alumina (Al2O3).
11. Silica is combined with lead in glass due to which of the following reasons?
a) Reduce the leaching of sodium
b) Hardness and durability
c) Clarity and brilliance
d) Preventing the glass from dissolving in water
View Answer
Explanation: Silica is combined with lead in glass as lead provides clarity and brilliance to glass. Silica is combined with other raw materials in various proportions for the following reasons-
Alumina increases hardness and durability.
6% boron reduces the leaching of sodium.
Calcium and magnesium carbonates (limestone and dolomite) acts as stabilizers, preventing the glass from dissolving in water.
12. ______ is the spiral groove on the closure.
a) Face
b) Skirt
c) Panel
d) Thread
View Answer
Explanation: Thread is the spiral groove on the skirt of a continuous thread closure that meshes with the tread on the glass finish. Face is the outside of the cap. Panel is the flat center area in the top of the closure. Skirt is the flat, almost vertical portion on the side of the closure, which serves as the gripping surface and may be smooth, knurled or fluted.
13. Gasket in glass is also known as ________
a) liner
b) face
c) thread
d) reverse
View Answer
Explanation: Gasket or liner is the actual sealing component of the closure, which makes an intimate contact with the glass finish to form an effective seal. Gaskets are made from rubber or plastisols.
14. Which of the following is main function of lug-type or twist cap?
a) Closures to retain internal pressure
b) Closures to contain and protect contents
c) Closures to maintain vacuum inside container
d) Closures to secure contents inside containe
View Answer
Explanation: Closures used with food containers can be classified under four chidings. They are-
i. Closures to retain internal pressure – They retain an internal pressure of 200-800 kPa, as found in carbonated drinks and beer. Ex. Crown cork, Roll-on tamper evident aluminum closure
ii. Closures to contain and protect contents – They contain and protect the contents with no internal pressure (Ex. Wine in a bottle). Ex. Bark cork
iii. Closures to maintain vacuum inside container – They maintain a vacuum inside glass containers that typically contain heat-processed food. Ex. Lug-type or twist cap, Press-on twist –off cap, Pry-off (side seal) cap
iv. Closures to secure contents inside container – They are to secure the contents inside the glass container (Ex. Peanut butter).
15. Which of the following adds rigidity to the cap in glass closure?
a) Curl
b) Face
c) Lug
d) Reverse
View Answer
Explanation: Curl adds rigidity to the cap in glass closure. It also protects the cut edge of the metal. Curl is the round or rolled portion at the bottom of the skirt. Lug is a horizontal inward protrusion from the curl that is seated under the thread on the glass finish and holds the cap in position. Face is the outside of the cap. Reverse is the inside of the cap.
Sanfoundry Global Education & Learning Series – Food Packaging Technology.
To practice all areas of Food Packaging Technology for Quizzes, here is complete set of 1000+ Multiple Choice Questions and Answers.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
- Apply for Agricultural Engineering Internship
- Practice Agricultural Engineering MCQs
- Check Food Packaging Technology Books
- Check Agricultural Engineering Books
