1
NDA General Ability 16 April 2023
MCQ (Single Correct Answer)
+4
-1.33
Toothpaste prevents tooth decay by:
A
neutralizing the excess acidity.
B
means of emulsification.
C
the action of fluoride.
D
making a coat of calcium over the teeth surface.
2
NDA General Ability 16 April 2023
MCQ (Single Correct Answer)
+4
-1.33
Which one of the following statements about X-rays is not true?
A
They have wavelengths of about 1 Å.
B
These can be generated by bombarding a metal target by high energy electrons.
C
Due to their wavelengths being shorter, these can be used for radar systems.
D
These are also used for the treatment of certain forms of cancer.
3
NDA General Ability 16 April 2023
MCQ (Single Correct Answer)
+4
-1.33
Mica is mainly used in:
A
food and beverage industry.
B
iron and steel industry.
C
aluminium industry.
D
electrical and electronic industries.
4
NDA General Ability 16 April 2023
MCQ (Single Correct Answer)
+4
-1.33
What is the specific purpose of using potassium hydroxide during the saponification process?
A
To obtain soaps which are hard on the skin
B
To obtain soaps which are soft on the skin
C
To obtain natural fragrance
D
To make the saponification very economical