JEE Advanced paper is considered to be one of the toughest entrance exams in India. Moreover, this Physics is considered the toughest subject because it is the most application-based. The student needs to get the basics right and then move on to mastering advanced concepts. Units and Measurements consist of nearly about 3-4 % of marks in the Physics section.

**Q1. Statement 1: If error in measurement of distance and time are 3% and 2% respectively, error in calculation of velocity is 5%.**

Statement 2: Velocity = Distance / Time

Statement 2: Velocity = Distance / Time

**Q2. Statement 1: Impulse has the dimensions of force.**

**Statement 2: Impulse = force × time.**

Solution

(d)

Impulse = Force × time

∴ Impulse has no dimension of force

(d)

Impulse = Force × time

∴ Impulse has no dimension of force

**Q3. Statement 1: The graph between P and Q is straight line, when P/Q is constant**

Statement 2: The straight-line graph means that P proportional to Q or P is equal to constant multiplied by Q

Statement 2: The straight-line graph means that P proportional to Q or P is equal to constant multiplied by Q

Solution

(a)

According to statement of reason, as the graph is a straight line, P ∝ Q, or P = constant × Q i.e. P/Q = constant

(a)

According to statement of reason, as the graph is a straight line, P ∝ Q, or P = constant × Q i.e. P/Q = constant

**Q5. Statement 1: A.U. is much bigger than â„«**

Statement 2: A.U. stands for astronomical unit and â„« stands from Angstrom

Statement 2: A.U. stands for astronomical unit and â„« stands from Angstrom

Solution

(b)

A.U. (Astronomical unit) is used to measure the average distance of the centre of the sun from the centre of the earth, while angstrom is used for very short distances. 1 A.U. = 1.5 × 10

(b)

A.U. (Astronomical unit) is used to measure the average distance of the centre of the sun from the centre of the earth, while angstrom is used for very short distances. 1 A.U. = 1.5 × 10

^{-11}m ; 1â„« = 10^{-10}m**Q7. Statement 1: In y = A sin( Ï‰t - kx ), ( Ï‰t - kx ) is dimensionless**

Statement 2: Because dimension of Ï‰=[M

Statement 2: Because dimension of Ï‰=[M

^{0}L^{0}T]
Solution

(c)

As Ï‰ (angular velocity) has the dimension of [T

(c)

As Ï‰ (angular velocity) has the dimension of [T

^{-1}] not [T]**Q8. Statement 1: AU is much bigger than Ã….**

Statement 2: 1 AU = 1.5 × 10

Statement 2: 1 AU = 1.5 × 10

^{11}m and 1 Ã… = 10^{-10}m.**Q10. Statement 1: Mass, length and time are fundamental physical quantities**

Statement 2: They are independent of each other

Statement 2: They are independent of each other

Solution

(a)

As length, mass and time represent our basic scientific notations, therefore they are called fundamental quantities and they cannot be obtained from each other

(a)

As length, mass and time represent our basic scientific notations, therefore they are called fundamental quantities and they cannot be obtained from each other