## Units and Dimensions Quiz-3

**Dear Readers ,**

As per analysis for previous years, it has been observed that students preparing for NEET find Physics out of all the sections to be complex to handle and the majority of them are not able to comprehend the reason behind it. This problem arises especially because these aspirants appearing for the examination are more inclined to have a keen interest in Biology due to their medical background.

Furthermore, sections such as Physics are dominantly based on theories, laws, numerical in comparison to a section of Biology which is more of fact-based, life sciences, and includes substantial explanations. By using the table given below, you easily and directly access to the topics and respective links of MCQs. Moreover, to make learning smooth and efficient, all the questions come with their supportive solutions to make utilization of time even more productive. Students will be covered for all their studies as the topics are available from basics to even the most advanced.

**Q1.**A plate has a length (5±0.1)cm and breadth (2±0.01)cm. Then the area of the plate is

**Q2.**One yard in SI units is equal

(b) 1 yard=36 inch=36×2.54 cm=0.9144m

**Q3.**The dimensional formula for Boltzmann’s constant is

k=[R/N]=[ML

^{2}T

^{-2}Î¸

^{-1}]

**Q4.**Erg-m

^{-1}-1 can be the unit of measure for

(a) Energy (E)= F×d ⇒F=E/d So Erg/metre can be the unit of force

**Q5.**Which physical quantities have the same dimension

Couple of force = |r ×F |=[ML

^{2}T

^{-2}] Work =[F .d ]=[ML

^{2}T

^{-2}]

**Q6.**The frequency of vibration f of a mass m suspended from a spring of spring constant k is given by relation of the type f=cm

^{x}k

^{y}, where c is a dimensionless constant. The values of x and y are

[M

^{0}L

^{0}T

^{-1}]=[M

^{x}][M

^{y}T

^{2y}]=[M

^{x+y}T

^{-2y}] Equating powers of M and T. x+y=0,-2y=-1 Or y=1/2,x+1/2=0 or x=-1/2

**Q7.**What is the unit of k in the relation U=ky/(y

^{2}+a

^{2}) where U represents the potential energy, y represents the displacement and a represents the maximum displacement ie, amplitude?

(c) The right hand side of the given relation is basically k/metre. But, since the left hand side is joule, therefore k should be J m.

**Q8.**The pair having the same dimensions is

(b) Dimension of work and torque =[ML

^{2}T

^{-2}]

**Q9.**Which one has the dimensions different from the remaining three

Power = Energy/Time

**Q10.**Planck’s constant has the dimensions (unit) of

(d) [h]=[Angular momentum] =[ML

^{2}T

^{-1}]