Physics NCERT Exemplar Solutions Class 11th Chapter Two

This is a long answer type question as classified in NCERT Exemplar

According to kepler's law T² $\propto$  r³

T $\propto r^{3/2}$

T $\propto r^{\frac{3}{2}}{R}^a{g}^b$

T $\propto k{r}^{\frac{3}{2}}{R}^a{g}^b$

[M⁰L⁰T]=K [L]^3/2 [L]^a [LT^-2]^b

 = k [L^a+b+3/2T^-2b]

On comparing the powers of same terms we get

So a+b+3/2=0

So b=-1/2 and a=-1

T=kr^3/2R^-1g^-1/2

T= $\frac{k}{R}\sqrt[]{\frac{r^3}{g}}$

This is a long answer type question as classified in NCERT Exemplar

Dimensions of energy is E= [ML²T^-2]

Mass m= [M]

Dimension of E= [ML²T^-2]

Dimensions of L= [ML^-2T^-1]

Dimensions of G= [M^-1L³T^-2]

By using these values [P]= [ML²T^{-2] $*\left[\mathrm{M}{\mathrm{L}}^2{\mathrm{T}}^{-1}\right]$ 2 $[{\mathrm{M}]}^{-5}*[{\mathrm{M}}^{-1}{\mathrm{L}}^3{\mathrm{T}}^{-2}]$ -2}

= [M^1+2-5+2L^2+4-6T^-2-2+4]

= [M⁰L⁰T⁰]

After we know that P is dimensionless quantity

This is a long answer type question as classified in NCERT Exemplar

As we know that X= a² b³ c^5/2 d^-2

Maximum percentage error in X is $\frac{?X}{X}*100=\pm \left. [2\left(\frac{?a}{a}*100\right)+3\left(\frac{?b}{b}*100\right)+\frac{5}{2}\left(\frac{?c}{C}*100\right)+2\left(\frac{?d}{d}*100\right)\right]$

= $\pm \left. [2\left(1\right)+3\left(2\right)+\frac{5}{2}\left(3\right)+2\left(4\right)\right]\%$

$\pm [2+6+\frac{15}{2}+8]$

$=\pm 23.5\%$

Mean absolute error in X= $\pm 0.24$ rounding off to significant value.

And calculated value would be 2.8 rounding off upto two digits.

This is a long answer type question as classified in NCERT Exemplar

Rate of flow is equal to V= $\frac{\pi }{8}\frac{p{r}^4}{\eta l}$

Dimensions of V or LHS= volume/time=L³/T= [L³T^-1]

Dimensions of P= [ML^-1T^-2]

Dimensions of  $\eta$ = [ML^-1T^-1]

Dimensions of L= [L]

Dimensions of r= [L]

Dimensions of RHS= $\frac{\left[M{L}^{-1}{T}^{-2}\right]}{\left[M{L}^{-1}{T}^{-1}\right]}\frac{\left[L^4\right]}{\left[L\right]}=\left[L^3{T}^{-1}\right]$

So they are in equal in dimensions.

So equation is correct dimensionally.

This is a long answer type question as classified in NCERT Exemplar

Energy E= [ML²T^-2]

Let M₁, L₁ and T₁ and M₂, L₂ and T₂ are fundamental quantities for two units

M₁=1kg and L₁=1m and T₁=1s

M₂= α kg, L₂= β m and T₂= γ s

And n₁u₁=n₂u₂

The NCERT Exemplar provides great study material for preparing for the exam. It can help immensely in scoring high in the class 11 Physics exam. It helps in strengthening the concepts and improving understanding of how to solve complex problems. However, it is advised that it should be practiced alongside the NCERT textbook. The students can first read the theory from the NCERT book and then study from the NCERT Exemplar to apply the theory in solving questions. The Exemplar is a great tool for practice and revision.

Yes, the NCERT Exemplar is extremely important for entrance exam preparation. Those who are preparing for the NEET and JEE examinations must have a clear understanding of all the topics related to the chapter. The NCERT Exemplar contains advanced-level questions that are based on chapter 1 concepts and also similar questions those asked in the competitive exams. Practicing from Shiksha's NCERT Exemplar gives concept clarity, speed, and accuracy while solving the questions in CBSE or entrance exams.

The NCERT Exemplar provides a variety of higher-order thinking and application-based questions. It helps students deepen their understanding of Chapter Two Units and Measurements. The chapter helps students build a strong foundation for Physics advanced topics, prepares students for competitive exams, and improves their problem-solving skills.