Question
_______ acts as a lubricant in making pencils.
- Graphite
- Diamond
- Carbon
- Phosphorous
Hint:
The lubricant used in making pencils is a strong heat and energy conductor.
The correct answer is: Graphite
- Graphite acts as a lubricant in making pencils.
- The layers of graphite are held together by weak forces between the free electron of either layer.
Related Questions to study
Which of the following is a solid inert element?
Which of the following is a solid inert element?
Which of these is not the property of noble gases?
Which of these is not the property of noble gases?
_________ is used in dressing wounds.
_________ is used in dressing wounds.
Iodine test is used to check the presence of _________.
Iodine test is used to check the presence of _________.
___________ is used for bleaching cotton and jute fibers.
___________ is used for bleaching cotton and jute fibers.
Which element irritates the mucous membrane?
Which element irritates the mucous membrane?
Choose which one of the following fibers is the strongest.
Choose which one of the following fibers is the strongest.
Match the following.
Match the following.
Choose which of the following is the typical behaviour of plastic.
Choose which of the following is the typical behaviour of plastic.
____ is the synthetic fiber used to make parachutes.
The correct option is c)Nylon.
Nylon threads are very strong and can withstand high loads. As such, it is used to make parachutes and ropes for climbing. Nylon fibers are strong, elastic and shiny. It is easy to wash, dries quickly even after washing, and does not lose its shape. These properties make it ideal for making parachutes and raincoats.
____ is the synthetic fiber used to make parachutes.
The correct option is c)Nylon.
Nylon threads are very strong and can withstand high loads. As such, it is used to make parachutes and ropes for climbing. Nylon fibers are strong, elastic and shiny. It is easy to wash, dries quickly even after washing, and does not lose its shape. These properties make it ideal for making parachutes and raincoats.
Assertion: Nylon fibers cannot be used for making ropes for climbers.
Reason: Nylon fibers are very strong fibers.
Assertion: Nylon fibers cannot be used for making ropes for climbers.
Reason: Nylon fibers are very strong fibers.
Select the correct R principle for the statement. “To use something again that you would normally throw away.”
The correct option is b)Reuse.
Reuse is the act or practice of using an item, whether for its original purpose or to perform some other function. This should be distinguished from recycling, which dismantles used items to produce raw materials for manufacturing new products.
Select the correct R principle for the statement. “To use something again that you would normally throw away.”
The correct option is b)Reuse.
Reuse is the act or practice of using an item, whether for its original purpose or to perform some other function. This should be distinguished from recycling, which dismantles used items to produce raw materials for manufacturing new products.
Ester is used in repeating units in the making of polyester. Choose true or false.
The statement is true.
- Polyester is a man-made or synthetic fiber made up of repeating units of chemicals called esters.
- Esters are sweet-smelling compounds composed primarily of carbon, hydrogen, and oxygen.
- The most commonly used polyester formula is: As an ester, it is made from the acid benzene-1,4-dicarboxylic acid (terephthalic acid) and the alcohol ethane-1,2-diol.
- It is better known by the mundane name of polyethylene terephthalate (PET).
Ester is used in repeating units in the making of polyester. Choose true or false.
The statement is true.
- Polyester is a man-made or synthetic fiber made up of repeating units of chemicals called esters.
- Esters are sweet-smelling compounds composed primarily of carbon, hydrogen, and oxygen.
- The most commonly used polyester formula is: As an ester, it is made from the acid benzene-1,4-dicarboxylic acid (terephthalic acid) and the alcohol ethane-1,2-diol.
- It is better known by the mundane name of polyethylene terephthalate (PET).
Select the other name for artificial silk.
The correct option is b)Rayon.
Rayon is a semi-synthetic fiber made from natural sources of regenerated cellulose such as wood and related agricultural products. It has the same molecular structure as cellulose. Also called viscose. Viscose fibers and films come in many types and qualities.
Select the other name for artificial silk.
The correct option is b)Rayon.
Rayon is a semi-synthetic fiber made from natural sources of regenerated cellulose such as wood and related agricultural products. It has the same molecular structure as cellulose. Also called viscose. Viscose fibers and films come in many types and qualities.
Choose the fiber which is termed artificial wool.
The correct option is b)Acrylic.
- Polyester is a synthetic fiber obtained from coal or petroleum.
- Polyester is durable but breathable and not designed to absorb liquids.
- Acrylic fibers are made using acrylonitrile or vinyl cyanide polymers.
- Acrylic is often considered an imitation of wool because it retains heat.
Choose the fiber which is termed artificial wool.
The correct option is b)Acrylic.
- Polyester is a synthetic fiber obtained from coal or petroleum.
- Polyester is durable but breathable and not designed to absorb liquids.
- Acrylic fibers are made using acrylonitrile or vinyl cyanide polymers.
- Acrylic is often considered an imitation of wool because it retains heat.
