# Units and Measurement Test 3

Total Questions:50 Total Time: 60 Min

Remaining:

## Questions 1 of 50

Question:A micron is related to centimetre as

$$1\,micron = {10^{ - 8}}cm$$

$$1\,micron = {10^{ - 6}}cm$$

$$1\,micron = {10^{ - 5}}cm$$

$$1\,micron = {10^{ - 4}}\,cm$$

## Questions 2 of 50

Question:The unit of power is

Joule

Joule per second only

Joule per second and watt both

Only watt

## Questions 3 of 50

Question:A suitable unit for gravitational constant is

$$kg{\rm{ - }}\,m{\sec ^{ - 1}}$$

$$N\;{m^{ - 1}}\sec$$

$$N\,\,{m^2}\,k{g^{ - 2}}$$

$$kg\,m\,{\sec ^{ - 1}}$$

## Questions 4 of 50

Question:Unit of energy is

$$J/\sec$$

$$Watt - day$$

$$Kilowatt$$

$$gm{\rm{ - }}cm/{\sec ^2}$$

## Questions 5 of 50

Question:Which is the correct unit for measuring nuclear radii

Micron

Millimetre

Angstrom

Fermi

## Questions 6 of 50

Question:One Mach number is equal to

Velocity of light

Velocity of sound $$(332\,\,m/\sec )$$

$$1\,\,km/\sec$$

$$1\,m/\sec$$

## Questions 7 of 50

Question:$$Kilowatt - hour$$ is a unit of

Electrical charge

Energy

Power

Force

## Questions 8 of 50

Question:What is the SI unit of permeability

Henry per metre

Tesla metre per ampere

Weber per ampere metre

All the above units are correct

## Questions 9 of 50

Question:In which of the following systems of unit, $$Weber$$ is the unit of magnetic flux

CGS

MKS

SI

None of these

## Questions 10 of 50

Question:Unit of stress is

$$N/m$$

$$N - m$$

$$N/{m^2}$$

$$N - {m^2}$$

## Questions 11 of 50

Question:Unit of Stefan's constant is

$$J\,{s^{ - 1}}$$

$$J\,{m^{ - 2}}{s^{ - 1}}{K^{ - 4}}$$

$$J\,{m^{ - 2}}$$

$$J\,s$$

## Questions 12 of 50

Question:Unit of magnetic moment is

$$Ampere - metr{e^2}$$

$$Ampere - metre$$

$$Weber - metr{e^2}$$

$$Weber/metre$$

## Questions 13 of 50

Question:The unit of absolute permittivity is

$$Fm$$ (Farad-meter)

$$F{m^{ - 1}}$$ (Farad/meter)

$$F{m^{ - 2}}$$(Farad/$$metr{e^2}$$)

$$F$$ (Farad)

None of these

## Questions 14 of 50

Question:Which relation is wrong

1 Calorie = 4.18 Joules

$$1{\AA} = {10^{ - 10}}m$$

$$1\,\,MeV = 1.6 \times {10^{ - 13}}Joules$$

$$1\,Newton = {10^{ - 5}}Dynes$$

## Questions 15 of 50

Question:If $$x = at + b{t^2}$$, where $$x$$ is the distance travelled by the body in kilometres while $$t$$ is the time in seconds, then the units of b are

$$km/s$$

$$km - s$$

$$km/{s^2}$$

$$km - {s^2}$$

## Questions 16 of 50

Question:In C.G.S. system the magnitutde of the force is 100 dynes. In another system where the fundamental physical quantities are kilogram, metre and minute, the magnitude of the force is

0.04

0.36

3.6

36

## Questions 17 of 50

Question:The unit of $$L/R$$ is (where $$L$$ = inductance and $$R$$ = resistance)

$$\sec$$

$${\sec ^{ - 1}}$$

Volt

Ampere

## Questions 18 of 50

Question:Which is different from others by units

Phase difference

Mechanical equivalent

Loudness of sound

Poisson's ratio

## Questions 19 of 50

Question:The unit of Youngâ€™s modulus is

$$N{m^2}$$

$$N{m^{ - 2}}$$

Nm

$$N{m^{ - 1}}$$

## Questions 20 of 50

Question:One femtometer is equivalent to

$${10^{15}}\,m$$

$${10^{ - 15}}\,m$$

$${10^{ - 12}}\,m$$

$${10^{12}}\,m$$

## Questions 21 of 50

Question:How many wavelength of $$K{r^{86}}$$ are there in one metre

1553164.13

1650763.73

652189.63

2348123.73

## Questions 22 of 50

Question:The dimensional formula of angular velocity is

$${M^0}{L^0}{T^{ - 1}}$$

$$ML{T^{ - 1}}$$

$${M^0}{L^0}{T^1}$$

$$M{L^0}{T^{ - 2}}$$

## Questions 23 of 50

Question:The dimensions of power are

$${M^1}{L^2}{T^{ - 3}}$$

$${M^2}{L^1}{T^{ - 2}}$$

$${M^1}{L^2}{T^{ - 1}}$$

$${M^1}{L^1}{T^{ - 2}}$$

## Questions 24 of 50

Question:The dimensions of couple are

$$M{L^2}{T^{ - 2}}$$

$$ML{T^{ - 2}}$$

$$M{L^{ - 1}}{T^{ - 3}}$$

$$M{L^{ - 2}}{T^{ - 2}}$$

## Questions 25 of 50

Question:A spherical body of mass $$m$$ and radius $$r$$ is allowed to fall in a medium of viscosity $$\eta$$. The time in which the velocity of the body increases from zero to 0.63 times the terminal velocity $$(v)$$ is called time constant $$(\tau )$$ . Dimensionally $$\tau$$ can be represented by

$$\frac{{m{r^2}}}{{6\pi \eta }}$$

$$\sqrt {\left( {\frac{{6\pi mr\eta }}{{{g^2}}}} \right)}$$

$$\frac{m}{{6\pi \eta rv}}$$

None of the above

## Questions 26 of 50

Question:The frequency of vibration $$f$$ of a mass $$m$$ suspended from a spring of spring constant $$K$$is given by a relation of this type $$f = C\,{m^x}{K^y}$$; where $$C$$ is a dimensionless quantity. The value of $$x$$ and $$y$$ are

$$x = \frac{1}{2},\,y = \frac{1}{2}$$

$$x = - \frac{1}{2},\,y = - \frac{1}{2}$$

$$x = \frac{1}{2},\,y = - \frac{1}{2}$$

$$x = - \frac{1}{2},\,y = \frac{1}{2}$$

## Questions 27 of 50

Question:The quantities $$A$$and $$B$$ are related by the relation, $$m = A/B$$, where $$m$$ is the linear density and $$A$$ is the force. The dimensions of $$B$$ are of

Pressure

Work

Latent heat

None of the above

## Questions 28 of 50

Question:The period of a body under SHM i.e. presented by $$T = {P^a}{D^b}{S^c}$$; where $$P$$ is pressure, $$D$$ is density and $$S$$ is surface tension. The value of $$a,\,b$$ and $$c$$ are

$$- \frac{3}{2},\,\frac{1}{2},\,1$$

$$- 1,\, - 2,\,3$$

$$\frac{1}{2},\, - \frac{3}{2},\, - \frac{1}{2}$$

$$1,\,2,\,\frac{1}{3}$$

## Questions 29 of 50

Question:Which of the following pairs of physical quantities has the same dimensions

Work and power

Momentum and energy

Force and power

Work and energy

## Questions 30 of 50

Question:The velocity of a freely falling body changes as $${g^p}{h^q}$$ where g is acceleration due to gravity and $$h$$ is the height. The values of $$p$$ and $$q$$ are

$$1,\frac{1}{2}$$

$${M^0}{L^2}{T^{ - 2}}$$

$$\frac{1}{2},\,1$$

$$1,\,1$$

## Questions 31 of 50

Question:The dimensional formula of wave number is

$${M^0}{L^0}{T^{ - 1}}$$

$${M^0}{L^{ - 1}}{T^0}$$

$${M^{ - 1}}{L^{ - 1}}{T^0}$$

$${M^0}{L^0}{T^0}$$

## Questions 32 of 50

Question:The dimensions of stress are equal to

Force

Pressure

Work

$$\frac{1}{{{\rm{Pressure}}}}$$

## Questions 33 of 50

Question:The dimensions of surface tension are

$$M{L^{ - 1}}{T^{ - 2}}$$

$$ML{T^{ - 2}}$$

$$M{L^{ - 1}}{T^{ - 1}}$$

$$M{T^{ - 2}}$$

## Questions 34 of 50

Question:In the following list, the only pair which have different dimensions, is

Linear momentum and moment of a force

Planck's constant and angular momentum

Pressure and modulus of elasticity

Torque and potential energy

## Questions 35 of 50

Question:If $$R$$ and $$L$$ represent respectively resistance and self inductance, which of the following combinations has the dimensions of frequency

$$\frac{R}{L}$$

$$\frac{L}{R}$$

$$\sqrt {\frac{R}{L}}$$

$$\sqrt {\frac{L}{R}}$$

## Questions 36 of 50

Question:The physical quantity which has the dimensional formula $${M^1}{T^{ - 3}}$$ is

Surface tension

Solar constant

Density

Compressibility

## Questions 37 of 50

Question:A force $$F$$ is given by $$F = at + b{t^2}$$, where $$t$$ is time. What are the dimensions of $$a$$ and $$b$$

$$ML{T^{ - 3}}$$ and $$M{L^2}{T^{ - 4}}$$

$$ML{T^{ - 3}}$$ and $$ML{T^{ - 4}}$$

$$ML{T^{ - 1}}$$ and $$ML{T^0}$$

$$ML{T^{ - 4}}$$ and $$ML{T^1}$$

## Questions 38 of 50

Question:The dimensions of inter atomic force constant are

$$M{T^{ - 2}}$$

$$ML{T^{ - 1}}$$

$$ML{T^{ - 2}}$$

$$M{L^{ - 1}}{T^{ - 1}}$$

## Questions 39 of 50

Question:The dimensional formula $${M^0}{L^2}{T^{ - 2}}$$ stands for

Torque

Angular momentum

Latent heat

Coefficient of thermal conductivity

## Questions 40 of 50

Question:Which of the following represents the dimensions of Farad

$${M^{ - 1}}{L^{ - 2}}{T^4}{A^2}$$

$$M{L^2}{T^2}{A^{ - 2}}$$

$$M{L^2}{T^2}{A^{ - 1}}$$

$$M{T^{ - 2}}{A^{ - 1}}$$

## Questions 41 of 50

Question:If $$L,\,C$$ and $$R$$ denote the inductance, capacitance and resistance respectively, the dimensional formula for $${C^2}LR$$ is

$$[M{L^{ - 2}}{T^{ - 1}}{I^0}]$$

$$[{M^0}{L^0}{T^3}{I^0}]$$

$$[{M^{ - 1}}{L^{ - 2}}{T^6}{I^2}]$$

$$[{M^0}{L^0}{T^2}{I^0}]$$

## Questions 42 of 50

Question:The dimensional formula of relative density is [CPMT 2003]

$$M{L^{ - 3}}$$

$$L{T^{ - 1}}$$

$$ML{T^{ - 2}}$$

Dimensionless

## Questions 43 of 50

Question:The dimensional formula for young's modulus is

$$M{L^{ - 1}}{T^{ - 2}}$$

$${M^0}L{T^{ - 2}}$$

$$ML{T^{ - 2}}$$

$$M{L^2}{T^{ - 2}}$$

## Questions 44 of 50

Question:Frequency is the function of density $$(\rho )$$, length  and surface tension $$(T)$$. Then its value is

$$k{\rho ^{1/2}}{a^{3/2}}{\bf{/}}\sqrt T$$

$$k{\rho ^{3/2}}{a^{3/2}}/\sqrt T$$

$$k{\rho ^{1/2}}{a^{3/2}}/{T^{3/4}}$$

$$k{\rho ^{1/2}}{a^{1/2}}/{T^{3/2}}$$

## Questions 45 of 50

Question:Which of the following group have different dimension

Potential difference, EMF, voltage

Pressure, stress, young's modulus

Heat, energy, work-done

Dipole moment, electric flux, electric field

## Questions 46 of 50

Question:Out of following four dimensional quantities, which one quantity is to be called a dimensional constant

cceleration due to gravity

Surface tension of water

Weight of a standard kilogram mass

The velocity of light in vacuum

## Questions 47 of 50

Question:Density of a liquid in CGS system is 0.625$$g/c{m^3}$$. What is its magnitude in SI system

0.63

0.06

0.01

625

## Questions 48 of 50

Question:In the context of accuracy of measurement and significant figures in expressing results of experiment, which of the following is/are correct (1) Out of the two measurements 50.14 cm and 0.00025 ampere, the first one has greater accuracy (2) If one travels 478 km by rail and 397 m. by road, the total

distance travelled is 478 km.

Only (1) is correct

Only (2) is correct

Both are correct

None of them is correct.

## Questions 49 of 50

Question:A physical parameter a can be determined by measuring the parameters b, c, d and e using the relation a = $${b^\alpha }{c^\beta }/{d^\gamma }{e^\delta }$$. If the maximum errors in the measurement of b, c, d and e are $${b_1}$$%, $${c_1}$$%, $${d_1}$$% and $${e_1}$$%, then the maximum error in the value of a determined by the experiment is

($${b_1}\, + \,{c_1}\, + \,{d_1}\, + \,{e_1}$$)%

($${b_{1\,}}\, + \,{c_1}\, - \,{d_1}\, - \,{e_1}$$)%

($$\alpha {b_1}\, + \,\beta {c_1}\, - \,\gamma {d_1}\, - \delta {e_1}$$)%

($$\alpha {b_1} + \,\beta {c_1}\, + \,\gamma {d_1}\, + \,\delta {e_1}$$)%

## Questions 50 of 50

Question:The relative density of material of a body is found by weighing it first in air and then in water. If the weight in air is (5.00$$\pm 0.05$$) Newton and weight in water is (4.00$$\pm$$0.05) Newton. Then the relative density along with the maximum permissible percentage error is

5.0 $$\pm$$11%
5.0 $$\pm$$1%
5.0 $$\pm$$6%
1.25 $$\pm$$5%