Question : What is the full form of ISDN?

Option 1: International Service Digital Network

Option 2: Indian Service Digital Network

Option 3: Integrated Service Digital Network

Option 4: Internal Service Digital Network

Question : If $a^{3}+\frac{1}{a^{3}}=2$, then the value of $\frac{a^{2}+1}{a}$ is ($a$ is a positive number):

Option 1: 1

Option 2: 2

Option 3: 3

Option 4: 4

Question : If $(a+\frac{1}{a})^2=3$, the value of $(a^3+\frac{1}{a^3})$ is:

Option 1: $0$

Option 2: $3(a+\frac{1}{a})$

Option 3: $3(a^2+\frac{1}{a^2})$

Option 4: $1$

Question : If $a+b=1$, then $a^4+b^4-a^3-b^3-2a^2b^2+ab$ is equal to:

Option 1: 1

Option 2: 2

Option 3: 4

Option 4: 0

Question : If $(2+\sqrt{3})a=(2-\sqrt{3})b=1$, then the value of $\frac{1}{a}+\frac{1}{b}$ is:

Option 1: $1$

Option 2: $2$

Option 3: $2\sqrt{3}$

Option 4: $4$