NEET > sBlock Element (Alkali and Alkaline earth metals

Explore popular questions from sBlock Element (Alkali and Alkaline earth metals for NEET. This collection covers sBlock Element (Alkali and Alkaline earth metals previous year NEET questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

The density of material in CGS system of units is {tex} 4 \mathrm { g } / \mathrm { cm } ^ { 3 } . {/tex} In a system of units in which unit of length is 10{tex} \mathrm { cm } {/tex} and unit of mass is 100{tex} \mathrm { g } {/tex} , the value of density of material will be

A

0.4 unit

40 unit

C

400 unit

D

0.04 unit

Explanation

Q 2.    

Correct4

Incorrect-1

The time period of a body under S.H.M. is represented by: {tex} \mathrm { T } = \mathrm { P } ^ { \mathrm { a } } \mathrm { D } ^ { \mathrm { b } } \mathrm { S } ^ { \mathrm { c } } {/tex} where {tex} \mathrm { P } {/tex} is pressure, {tex} \mathrm { D } {/tex} is density and {tex} \mathrm { S } {/tex} is surface tension, then values of {tex} \mathrm { a } , \mathrm { b } {/tex} and {tex} \mathrm { c } {/tex} are

{tex} - \frac { 3 } { 2 } , \frac { 1 } { 2 } , 1 {/tex}

B

{tex} - 1 , - 2,3 {/tex}

C

{tex} \frac { 1 } { 2 } , - \frac { 3 } { 2 } , - \frac { 1 } { 2 } {/tex}

D

{tex} 1,2 , \frac { 1 } { 3 } {/tex}

Explanation

Q 3.    

Correct4

Incorrect-1

The respective number of significant figures for the numbers {tex} 23.023,0.0003 {/tex} and {tex} 2.1 \times 10 ^ { - 3 } {/tex} are

{tex} 5,1,2 {/tex}

B

{tex} 5,1,5 {/tex}

C

{tex} 5,5,2 {/tex}

D

{tex} 4,4,2 {/tex}

Explanation

Q 4.    

Correct4

Incorrect-1

Young's modulus of a material has the same unit as that of

pressure

B

strain

C

compressibility

D

force

Explanation

Q 5.    

Correct4

Incorrect-1

Of the following quantities, which one has dimensions different from the remaining three?

A

Energy per unit volume

B

Force per unit area

C

Product of voltage and charge per unit volume

Angular momentum

Explanation

Q 6.    

Correct4

Incorrect-1

The pressure on a square plate is measured by measuring the force on the plate and length of the sides of the plate by using the formula {tex} P = \frac { F } { \ell ^ { 2 } } {/tex} . If the maximum errors in the measurement of force and length are 4{tex} \% {/tex} and 2{tex} \% {/tex} respectively, then the maximum error in the measurement of pressure is

A

1{tex} \% {/tex}

B

2{tex} \% {/tex}

8{tex} \% {/tex}

D

10{tex} \% {/tex}

Explanation

Q 7.    

Correct4

Incorrect-1

The siemen is the SI unit of

A

resistivity

B

resistance

C

conductivity

conductance

Explanation

Q 8.    

Correct4

Incorrect-1

An object is moving through the liquid. The viscous damping force acting on it is proportional to the velocity. Then dimensions of constant of proportionality are

A

{tex} \left[ \mathrm { ML } ^ { - 1 } \mathrm { T } ^ { - 1 } \right] {/tex}

B

{tex} \left[ \mathrm { MLT } ^ { - 1 } \right] {/tex}

C

{tex} \left[ \mathrm { M } ^ { 0 } \mathrm { L T} ^ { -1 } \right] {/tex}

{tex} \left[ \mathrm { ML } ^ { 0 } \mathrm { T } ^ { - 1 } \right] {/tex}

Explanation

Q 9.    

Correct4

Incorrect-1

The least count of a stop watch is 0.2 second. The time of 20 oscillations of a pendulum is measured to be 25 second. The percentage error in the measurement of time will be

A

8{tex} \% {/tex}

B

1.8{tex} \% {/tex}

0.8{tex} \% {/tex}

D

0.1{tex} \% {/tex}

Explanation

Q 10.    

Correct4

Incorrect-1

Weber is the unit of

A

magnetic susceptibility

B

intensity of magnetisation

magnetic flux

D

magnetic permeability

Explanation

Q 11.    

Correct4

Incorrect-1

The physical quantity which has the dimensional formula {tex} \left[ \mathrm { M } ^ { 1 } \mathrm { T } ^ { - 3 } \right] {/tex} is

A

surface tension

solar constant

C

density

D

compressibility

Explanation

Q 12.    

Correct4

Incorrect-1

The dimensions of Wien's constant are

A

{tex} \left[ \mathrm { ML } ^ { 0 } \mathrm { T } \mathrm { K } \right] {/tex}

{tex} \left[ \mathrm { M } ^ { 0 } \mathrm { LT } ^ { 0 } \mathrm { K } \right] {/tex}

C

{tex} \left[ \mathrm { M } ^ { 0 } \mathrm { L } ^ { 0 } \mathrm { T } \mathrm { K } \right] {/tex}

D

{tex} [ \mathrm { MLTK } ] {/tex}

Explanation

Q 13.    

Correct4

Incorrect-1

If the capacitance of a nanocapacitor is measured in terms of a unit {tex}'u'{/tex} made by combining the electric charge {tex}'e'{/tex}, Bohr radius {tex}'a_o'{/tex} , Planck's constant 'h' and speed Of light {tex}'c'{/tex} then

A

{tex} \mathrm { u } = \frac { \mathrm { e } ^ { 2 } \mathrm { h } } { \mathrm { a } _ { 0 } } {/tex}

B

{tex} \mathrm { u } = \frac { \mathrm { hc } } { \mathrm { e } ^ { 2 } \mathrm { a } _ { 0 } } {/tex}

C

{tex} \mathrm { u } = \frac { \mathrm { e } ^ { 2 } \mathrm { c } } { \mathrm { ha } _ { 0 } } {/tex}

{tex} \mathrm { u } = \frac { \mathrm { e } ^ { 2 } \mathrm { a } _ { 0 } } { \mathrm { hc } } {/tex}

Explanation

Q 14.    

Correct4

Incorrect-1

The dimensions of {tex} \frac { 1 } { \epsilon _ { \mathrm { o } } } \frac { \mathrm { e } ^ { 2 } } { \mathrm { hc } } {/tex} are

A

{tex} \mathrm { M } ^ { - 1 } \mathrm { L } ^ { - 3 } \mathrm { T } ^ { 4 } \mathrm { A } ^ { 2 } {/tex}

B

{tex} \mathrm { ML } ^ { 3 } \mathrm { T } ^ { - 4 } \mathrm { A } ^ { - 2 } {/tex}

{tex} { M } ^ { 0 } { L } ^ { 0 } { T } ^ { 0 } { A } ^ { 0 } {/tex}

D

{tex} \mathrm { M } ^ { - 1 } \mathrm { L } ^ { - 3 } \mathrm { T } ^ { 2 } \mathrm { A } {/tex}

Explanation

Q 15.    

Correct4

Incorrect-1

The density of a cube is measured by measuring its mass and length of its sides. If the maximum error in the measurement of mass and length are 4{tex} \% {/tex} and 3{tex} \% {/tex} respectively, the maximum error in the measurement of density will be

A

7{tex} \% {/tex}

B

9{tex} \% {/tex}

C

12{tex} \% {/tex}

13{tex} \% {/tex}

Explanation

Q 16.    

Correct4

Incorrect-1

Which is different from others by units?

A

Phase difference

B

Mechanical equivalent

C

Loudness of sound

Poisson's ratio

Explanation

Q 17.    

Correct4

Incorrect-1

A quantity {tex} X {/tex} is given by {tex} \varepsilon _ { 0 } L \frac { \Delta V } { \Delta t } {/tex} where {tex} \epsilon _ { 0 } {/tex} is the permittivity of the free space, {tex} L {/tex} is a length, DV is a potential difference and Dt is a time interval. The dimensional formula for {tex} X {/tex} is the same as that of

A

resistance

B

charge

C

voltage

current

Explanation

Q 18.    

Correct4

Incorrect-1

If the error in the measurement of the volume of sphere is {tex} 6 \% , {/tex} then the error in the measurement of its surface area will be

A

2{tex} \% {/tex}

B

3{tex} \% {/tex}

4{tex} \% {/tex}

D

7.5{tex} \% {/tex}

Explanation

Q 19.    

Correct4

Incorrect-1

If velocity {tex} ( \mathrm { V } ) , {/tex} force {tex} ( \mathrm { F } ) {/tex} and energy {tex} ( \mathrm { E } ) {/tex} are taken as fundamental units, then dimensional formula for mass will be

A

{tex} \mathrm { V } ^ { - 2 } \mathrm { F } ^ { 0 } \mathrm { E } {/tex}

B

{tex} V^0FE^2{/tex}

C

{tex} \mathrm { VF } ^ { - 2 } \mathrm { E } ^ { 0 } {/tex}

{tex} \mathrm { V } ^ { - 2 } \mathrm { F } ^ { 0 } \mathrm { E } {/tex}

Explanation



Q 20.    

Correct4

Incorrect-1

Multiply 107.88 by 0.610 and express the result with correct number of significant figures.

A

65.8068

B

65.807

C

65.81

65.8

Explanation

Q 21.    

Correct4

Incorrect-1

Which of the following is a dimensional constant?

A

Refractive index

B

Poissons ratio

C

Strain

Gravitational constant

Explanation

Q 22.    

Correct4

Incorrect-1

If {tex} \mathrm { E } , \mathrm { m } , \mathrm { J } {/tex} and {tex} \mathrm { G } {/tex} represent energy, mass, angular momentum and gravitational constant respectively, then the dimensional formula of {tex} \mathrm { E } \mathrm { J } ^ { 2 } / \mathrm { m } ^ { 5 } \mathrm { G } ^ { 2 } {/tex} is same as that of the

angle

B

length

C

mass

D

time

Explanation

Q 23.    

Correct4

Incorrect-1

The refractive index of water measured by the relation {tex} \mathrm { m } = \frac { \text { real depth } } { \text { apparent depth } } {/tex} is found to have values of {tex} 1.34, 1.38, 1.32 {/tex} and {tex} 1.36 ; {/tex} the mean value of refractive index with percentage error is

{tex} 1.35 \pm 1.48 \% {/tex}

B

{tex} 1.35 \pm 0 \% {/tex}

C

{tex} 1.36 \pm 6 \% {/tex}

D

{tex} 1.36 \pm 0 \% {/tex}

Explanation

Q 24.    

Correct4

Incorrect-1

If e is the charge, {tex} V {/tex} the potential difference, T the temperature, then the units of {tex} \frac { \mathrm { eV } } { \mathrm { T } } {/tex} are the same as that of

A

Planck's constant

B

Stefan's constant

Boltzmann's constant

D

gravitational constant

Explanation

Q 25.    

Correct4

Incorrect-1

The dimensions of mobility are

A

{tex} \mathrm { M } ^ { - 2 } \mathrm { T } ^ { 2 } \mathrm { A } {/tex}

{tex} \mathrm { M } ^ { - 1 } \mathrm { T } ^ { 2 } \mathrm{ A } {/tex}

C

{tex} \mathrm { M } ^ { - 2 } \mathrm { T } ^ { 3 } \mathrm { A } {/tex}

D

{tex} \mathrm { M } ^ { - 1 } \mathrm { T } ^ { 3 } \mathrm { A } {/tex}

Explanation