Get Answers to all your Questions

Filter By

Clear Filter

All Questions

A particle is moving along the x- axis with its coordinate with time 't' given by $x(t)=10+8t-3t^2$ . Another particle is moving along the y-axis with its coordinate as a function of time given by $y(t)=5-8t^3.$ At $t=1$ s, the speed of the second particle measured in the frame of the first particle is given by $\sqrt{v}$ . Then $v$ (in m/s) is ____________.
Option: 1 580
Option: 2 700
Option: 3 100
Option: 4 300

$\begin{aligned} &x_{A}=-3 t^{2}+8 t+10 \\ &\vec{v}_{A}=(-6 t+8) \hat{i} \\ &\text { At time } t=1 \mathrm{~s} \\ &\vec{v}_{A}=2 \hat{i} \\ &Y_{B}=5-8 t^{3} \end{aligned}$

$\vec{v}_{B}=-24 t^{2} j$

At time t= 1 s

$\vec{v_{B}}=-24 \hat{j}$

$\begin{aligned} &\sqrt{v}=\left|\vec{v}_{B}-\vec{v}_{A}\right|=|-24 \hat{j}-2 \hat{i}| \\ &\sqrt{v}=\sqrt{580} \end{aligned}$

So the value of v is 580

View Full Answer(1)

Posted by

vishal kumar

The magnifying power of a telescope with tube length $60cm$ is $5$ . What is the focal length (in cm) of its eye piece?
Option: 1 30
Option: 2 40
Option: 3 10
Option: 4 20

$\begin{array}{l}{\text { Let the focal length of the objective as } f_{0}} \\ {\text { and focal length of the eyepiece as } f_{e}} \\ {\text { Magnifying power, } M=\frac{f_{0}}{f_{e}}} \\ {\text { Tube length, } L=f_{0}+f_{e}}\end{array}$

$\begin{array}{l}{\text { Given: Magnifying power }=5} \\ \\ {\therefore \frac{f_{0}}{f_{\mathrm{e}}}=5} \\ {\therefore {f}_{0}=5{f}_{e}} \\ and \ {\mathrm{L}=\mathrm{f}_{0}+\mathrm{f}_{\mathrm{e}}=60} \\ {5 \mathrm{f}_{\mathrm{e}}+\mathrm{f}_{\mathrm{e}}=60\quad\left[\because \mathrm{f}_{0}=5 \mathrm{f}_{\mathrm{e}}\right]} \\ {6\mathrm{f}_{\mathrm{e}}=60} \\ {\mathrm{f}_{\mathrm{e}}=\frac{60}{6}=10 \mathrm{cm}} \\ {\text { So the focal length of eye piece is } 10 \mathrm{cm} .}\end{array}$

So the correct answer is given in option 3.

View Full Answer(1)

Posted by

vishal kumar

Crack CUET with india's "Best Teachers"

HD Video Lectures
Unlimited Mock Tests
Faculty Support

The dimension of stopping potential $V_0$ in photoelectric effect in units of Planck's constant 'h', speed of light 'c' and Gravitational constant 'G' and ampere A is :
Option: 1 $h^{-2/3}c^{-1/3}G^{4/3}A^{-1}$

Option: 2 $[h]^0[G]^{-1}[c]^5[A]^{-1}$

Option: 3 $h^{2}G^{3/2}c^{1/3}A^{-1}$

Option: 4 $h^{1/3}G^{2/3}c^{1/3}A^{-1}$

Let $V_0=[h]^p[G]^q[c]^r[A]^s$

Now, $K_{max}=eV_0\Rightarrow [K_{max}]=[eV_0]\Rightarrow [V_0]=\frac{[K_{max}]}{[e]}\Rightarrow [V_0]=\frac{[ML^2T^{-2}]}{[AT]}$ $\therefore [V_0]=[ML^2T^{-3}A^{-1}]$

$E=hf\Rightarrow [h]=\frac{[E]}{[f]}\Rightarrow \frac{[ML^2T^{-2}]}{[T^{-1}]}\Rightarrow [h]=[ML^2T^{-1}]$

$F=\frac{Gm^2}{r^2}\Rightarrow [G]=\frac{[F][r^2]}{[m^2]}=\frac{[MLT^{-2}][L^2]}{[M^2]}=[M^{-1}L^3T^{-2}]$

So, $[ML^2T^{-3}A^{-1}]=[ML^2T^{-1}]^p[M^{-1}L^3T^{-2}]^q[LT^{-1}]^r[A]^s$

From here we will get: p-q=1---------(1)

2p+3q+r=2----------(2)

-p-2q-r=-3----------(3)

s=-1-----------(4)

From equation 1, 2,3 and 4 we will get: p=0,q=-1, r=5 and s=-1

So, $[V_0]=[h]^0[G]^{-1}[c]^5[A]^{-1}$

View Full Answer(1)

Posted by

vishal kumar

The critical angle (in degree)of a medium for a specific wavelength, if the medium has relative permitivity $3$ and relative permeability $\frac{4}{3}$ for this wavelength, will be :
Option: 1 15
Option: 2 30
Option: 3 45
Option: 4 60

$C_{vacuum}=\frac{1}{\sqrt{\mu _0\epsilon _0}} \ and \ C_{medium}=\frac{1}{\sqrt{\mu _0\mu _r\epsilon _0\epsilon _r}}$

and $n=\frac{C_{vacuum}}{C_{medium}}=\sqrt{\mu _r\epsilon _r} =\sqrt{\frac{4}{3}*3}=2$

By using snells law

$n*sinC=1*sin(90^0)\\ \Rightarrow n*sinC=1\\ \Rightarrow sinC=\frac{1}{2}\Rightarrow critical \ angle =C=30^0$

So the correct option is 2.

View Full Answer(1)

Posted by

vishal kumar

Crack NEET with "AI Coach"

HD Video Lectures
Unlimited Mock Tests
Faculty Support

Consider two solid sphers of radii $R_1=1m,\: R_2=2m$ and masses M₁ and M₂, respectively. The gravitational field due to sphere and are shown. The value of $\frac{M_1}{M_2}$ is:
Option: 1 $\frac{2}{3}$

Option: 2 $\frac{1}{6}$

Option: 3 $\frac{1}{2}$

Option: 4 $\frac{1}{3}$

Considering Case 2 and case 1, one by one

and using $I=\frac{GM}{R^2} \ \ \ \ (\text{Gravitational field on surface of sphere})$

R-Radius of sphere

$\\ 3=\frac{\mathrm{Gm}_{2}}{2^{2}} \\ \\ 2=\frac{\mathrm{Gm}_{1}}{1^{2}} \\ \\ \therefore \frac{3}{2}=\frac{1}{4} \frac{\mathrm{m}_{2}}{\mathrm{m}_{1}} \\ \\ \frac{\mathrm{m}_{1}}{\mathrm{m}_{2}}=\frac{1}{6}$

So the correct option is 2.

View Full Answer(1)

Posted by

vishal kumar

The major product $\left [ B \right ]$ in the following sequence of reaction is : $CH_{3}-\underset{CH(CH_{3})_{2}}{C}=CH-CH_{2}CH_{3}\xrightarrow[(i)H_{2}SO_{2},OH^{\ominus })]{(i)B_{2}H_{6}}\left [ A \right ]\xrightarrow[\Delta ]{dil.H_{2}SO_{4}}\left [ B \right ]$
Option: 1
Option: 2
Option: 3
Option: 4

Therefore, Option(3) is correct.

View Full Answer(1)

Posted by

Kuldeep Maurya

Crack JEE Main with "AI Coach"

HD Video Lectures
Unlimited Mock Tests
Faculty Support

Among the reactions (a) - (d), the reaction(s) that does / do not occur in the blast furnace during the extraction of iron is / are :

(a) $CaO+SiO_{2}\rightarrow CaSiO_{3}$ (b) $3Fe_{2}O_{3}+CO\rightarrow 2Fe_{3}O_{4}+CO_{2}$ (c) $FeO+SiO_{2}\rightarrow FeSiO_{3}$ (d) $FeO\rightarrow Fe+\frac{1}{2}O_{2}$
Option: 1 (C) and (D)

Option:2 (A)

Option: 3 (A) and (D)

Option: 4 (D)

The following reactions do not occur in the blast furnace:

C) $\mathrm{FeO}+\mathrm{SiO}_{2} \rightarrow \mathrm{FeSiO}_{3}$

D) $\mathrm{FeO} \rightarrow \mathrm{Fe}+\frac{1}{2} \mathrm{O}_{2}$

Therefore, Option(1) is correct.

View Full Answer(1)

Posted by

vishal kumar

The correct order of the calculated spin-only magnetic moments of complexes (A) to (D) is : (A) $Ni(CO)_{4}$ (B) $\left [ Ni(H_{2}O)_{6} \right ]Cl_{2}$ (C) $Na_{2}\left [ Ni(CN)_{4} \right ]$ (D) $PdCl_{2}(PPh_{3})_{2}$
Option: 1 $(A)\approx (C)< (B)\approx (D)$

Option: 2 $(C)\approx (D)< (B)< (A)$

Option: 3 $(C)< (D)< (B)< (A)$

Option: 4 $(A)\approx (C)\approx (D)< (B)$

As we have learnt,

$[Ni(CO)_4]$ contains $Ni(0)$ which has a $d^{10}$ configuration having $n=0$ and $\mu=0$

$[Ni(H_2O)_6]^{2+}$ contains $Ni^{2+}$ which has a $d^8$ configuration. In a weak ligand field, it has $n=2$ and hence has $\mu=\sqrt8 \ BM$

$[Ni(CN)]_4$ contains $Ni^{2+}$ which has a $d^8$ configuration. In a strong ligand field, these electrons get paired up and hence $n=0$ and $\mu =0$

$[Pd(PPh_3)_2Cl_2]$ contains $Pd^{2+}$ which has a $d^8$ configuration. These electrons get paired in the presence of strong ligand like $PPh_3$ and hence, $n=0$ and correspondingly $\mu=0$ .

Therefore, the correct order of spin only magnetic moment of the complexes is

$(B)>(A)=(C)=(D)$

Therefore, Option(4) is correct.

View Full Answer(1)

Posted by

vishal kumar

Crack CUET with india's "Best Teachers"

HD Video Lectures
Unlimited Mock Tests
Faculty Support

Arrange the following bonds according to their average bond energies in descending order : $C-Cl,\; C-Br,\; C-F,\; C-I$
Option: 1 $C-F> C-Cl> C-Br> C-I$

Option: 2 $C-Br> C-I> C-Cl> C-F$

Option: 3 $C-I> C-Br> C-Cl> C-F$

Option: 4 $C-Cl> C-Br> C-I> C-F$

The values of bond energies are given below:

$C-F\; \; \; \;\; -\; \; \; \; 485kJ/mol$

$C-Cl\; \; \; \;\; -\; \; \; \; 328kJ/mol$

$C-Br\; \; \; \;\; -\; \; \; \; 276kJ/mol$

$C-I\; \; \; \;\; -\; \; \; \; 240kJ/mol$

Thus, the correct order of bond energies is:

$C-F> C-Cl> C-Br> C-I$

Therefore, Option(1) is correct.

View Full Answer(1)

Posted by

vishal kumar

In the following reactions, products (A) and (B) respectively are: $NaOH + Cl_{2}\rightarrow A +NaCl+ side\ product$ (hot and conc.) $Ca(OH)_{2}+Cl_{2}\rightarrow B + CaCl_2+ side\ product$ (dry)
Option: 1 $NaClO_{3}\ and\ Ca(ClO_{3})_{2}$
Option: 2 $NaOCl\ and\ Ca(OCl)_{2}$
Option: 3 $NaClO_{_{3}}\ and\ Ca(OCl)_{2}$
Option: 4 $NaOCl\ and\ Ca(ClO_{3})_{2}$

As we have learnt,

Chlorine reacts with $NaOH$ and $Ca(OH)_2$ and undergoes disproportionation. The products depend upon the concentration of the base and also the temperature.

The reactions are given as

$2Na(OH) + 3 Cl_2 \longrightarrow NaClO_3 +5 NaCl + 3 H_2O$

(Hot and Conc.)

$2 Ca(OH)_2 + 2 Cl_2 \longrightarrow Ca(OCl)_2 + CaCl_2 + 2 H_2O$

(Dry)

Therefore, Option(4) is correct.

View Full Answer(1)

Posted by

Kuldeep Maurya

Crack NEET with "AI Coach"

HD Video Lectures
Unlimited Mock Tests
Faculty Support

Exams

Colleges

Predictors

Resources

Quick links

Quick Links

Exams

Colleges

Resources

Colleges

Resources

Exams

Exams

Colleges

Resources

Diploma Colleges

Other Exams

Exams

Resources

Upcoming Events

Exams

Ranking

Products & Resources

NCERT Solutions

Top Countries

Student Visas

Exams

Colleges

Exams

Colleges

Upcoming Events/Predictors

Resources

Exams

Colleges & Courses

Predictors

Resources

Online Courses

Products

Engineering Preparation

Medical Preparation

Top Streams

Specializations

Resources

Top Providers

Exams

Colleges

Predictors

Resources

Resources

Exams

Colleges

Predictors & E-Books

Exams

Animation Courses

Colleges

Resources

Exams

Colleges

Resources

Top Courses & Careers

Colleges

Exams

Resources

Get Answers to all your Questions

All Questions

Posted by

vishal kumar

The magnifying power of a telescope with tube length is . What is the focal length (in cm) of its eye piece? Option: 1 30 Option: 2 40 Option: 3 10 Option: 4 20

Posted by

vishal kumar

Crack CUET with india's "Best Teachers"

The dimension of stopping potential in photoelectric effect in units of Planck's constant 'h', speed of light 'c' and Gravitational constant 'G' and ampere A is : Option: 1 Option: 2 Option: 3 Option: 4

Posted by

vishal kumar

The critical angle (in degree)of a medium for a specific wavelength, if the medium has relative permitivity and relative permeability for this wavelength, will be : Option: 1 15 Option: 2 30 Option: 3 45 Option: 4 60

Posted by

vishal kumar

Crack NEET with "AI Coach"

Consider two solid sphers of radii and masses M1 and M2, respectively. The gravitational field due to sphere and are shown. The value of is: Option: 1 Option: 2 Option: 3 Option: 4

Posted by

The magnifying power of a telescope with tube length $60cm$ is $5$ . What is the focal length (in cm) of its eye piece?
Option: 1 30
Option: 2 40
Option: 3 10
Option: 4 20

The critical angle (in degree)of a medium for a specific wavelength, if the medium has relative permitivity $3$ and relative permeability $\frac{4}{3}$ for this wavelength, will be :
Option: 1 15
Option: 2 30
Option: 3 45
Option: 4 60

Consider two solid sphers of radii $R_1=1m,\: R_2=2m$ and masses M₁ and M₂, respectively. The gravitational field due to sphere and are shown. The value of $\frac{M_1}{M_2}$ is:
Option: 1 $\frac{2}{3}$

Option: 2 $\frac{1}{6}$

Option: 3 $\frac{1}{2}$

Option: 4 $\frac{1}{3}$

Arrange the following bonds according to their average bond energies in descending order : $C-Cl,\; C-Br,\; C-F,\; C-I$
Option: 1 $C-F> C-Cl> C-Br> C-I$

Option: 2 $C-Br> C-I> C-Cl> C-F$

Option: 3 $C-I> C-Br> C-Cl> C-F$

Option: 4 $C-Cl> C-Br> C-I> C-F$