Choose any one of the following four responses :

Assertion : The quantity (1/μ0ε0) is dimensionally equal to velocity and numerically equal to velocity of light.

Reason : μ0 is permeability of free space and ε0 is the permittivity of free space.

  • If both assertion and reason are true and the reason is the correct explanation of the assertion.

  • If both assertion and reason are true but reason is not the correct explanation of the assertion.

  • If assertion is true but reason is false.

  • If the assertion and reason both are false.

The surface tension of a liquid is 70 dyne/cm. In MKS system its value is 

  • 70 N/m

  • 7 × 10–2 N/m

  • 7 × 103 N/m

  • 7 × 102 N/m

The SI unit of universal gas constant (R) is

  • Watt K–1 mol–1

  • Newton K–1 mol–1

  • Joule K–1 mol–1

  • Erg K–1 mol–1

The unit of permittivity of free space ε0 is

  • Coulomb/Newton-metre

  • Newton-metre2/Coulomb2

  • Coulomb2/(Newton-metre)2

  • Coulomb2/Newton-metre2

What are the units of K=1/4πε0

  • C2N–1m–2

  • Nm2C–2

  • Nm2C2

  • Unitless

The SI unit of surface tension is

  • Dyne/cm

  • Newton/cm

  • Newton/metre

  • Newton-metre

E, m, l and G denote energy, mass, angular momentum and gravitational constant respectively, then the dimension of El2m5G2 are

  • Angle

  • Length

  • Mass

  • Time

One astronomical unit is a distance equal to 

  • 9.46×1015 m

  •  1.496×1011 m

  •  3×108 m

  •  3.08×1016 m 

Ampere second is a unit of 

  • Current 

  • Charge 

  • Energy 

  • Power 

A dimensionally consistent relation for the volume V of a liquid of coefficient of viscosity η flowing per second through a tube of radius r and length l and having a pressure difference p across its end, is

  • V=πpr48ηl

  • V=πηl8pr4

  • V=8pηlπr4

  • V=πpη8lr4

The velocity v (in cm/sec) of a particle is given in terms of time t (in sec) by the relation v=at+bt+c; the dimensions of a, b and c are

  • a=L2,b=T,c=LT2

  • a=LT2,b=LT,c=L

  • a=LT2,b=L,c=T

  • a=L,b=LT,c=T2

From the dimensional consideration, which of the following equation is correct ?

  • T=2πR3GM

  • T=2πGMR3

  • T=2πGMR2

  • T=2πR2GM

The position of a particle at time t is given by the relation l =voα(1-eαt) , where v0 is a constant and α > 0. The dimensions of v0 and α are respectively

  • M0L1T1 and T–1

  • M0L1T0 and T–1

  • M0L1T1 and LT–2

  • M0L1T1 and T

The dimensions of ab in the equation P=at2bx, where P is pressure, x is distance and t is time, are 

  • MT–2

  • M2LT–3

  • ML3T–1

  • LT–3

Dimensions of 1μ0ε0, where symbols have their usual meaning, are 

  • [LT–1]

  • [L–1T]

  • [L–2T2]

  • [L2T–2]

The dimensions of e2/4πε0hc, where e,ε0,h and c are electronic charge, electric permittivity, Planck’s constant and velocity of light in vacuum respectively 

  • [M0L0T0]

  • [M1L0T0]

  • [M0L1T0]

  • [M0L0T1]

If radius of the sphere is (5.3 ± 0.1)cm. Then percentage error in its volume will be 

  • 3+6.01×1005.3

  • 13×0.01×1005.3

  • 3×0.15.3×100

  • 0.15.3×100

The pressure on a square plate is measured by measuring the force on the plate and the length of the sides of the plate. If the maximum error in the measurement of force and length are respectively 4% and 2%. The maximum error in the measurement of pressure is 

  • 1%

  • 2%

  • 6%

  • 8%

While measuring the acceleration due to gravity by a simple pendulum, a student makes a positive error of 1% in the length of the pendulum and a negative error of 3% in the value of time period. His percentage error in the measurement of g by the relation g=4π2(l/T2) will be

  • 2%

  • 4%

  • 7%

  • 10%

The length, breadth, and thickness of a block are given by l = 12 cm, b = 6 cm and t = 2.45 cm The volume of the block according to the idea of significant figures should be:

  • 1 × 102 cm3

  • 2 × 102 cm3

  • 1.764 × 102 cm3

  • None of these

A physical quantity of the dimensions of length that can be formed out of c, G and e24πεο is [c is the velocity of light, G is the universal constant of gravitation and e is charge]

(a) 1c2Ge24πεo12

(b) c2Ge24πεo12

(c) 1c2e2G4πεo12

(d) 1cGe24πε0

  • 1
  • 2
  • 3
  • 4

Planck's constant (h),speed of light in vacuum (c) and Newton's gravitational constant (G) are three fundamental constants. Which of the following combinations of these has the dimensions of length?

  •  hGc3/2

  •  hGc5/2

  •  hcG

  • Gch3/2

If energy (E), velocity (v) and time (T) are chosen as the fundamental quantities, the dimensional formula of surface tension will be
 

  •  Ev-2T-1

  • [Ev-1T-2]

  •  Ev-2T-2

  • [E-2v-1T-3]

If dimensions of critical velocity vc of a liquid flowing through a tube are expressed as [ηxρyrz]  , where η, ρ and r are the coefficient of viscosity of the liquid, the density of liquid and radius of the tube respectively, then the values of x,y and z are given by

  • 1, -1, -1
  • -1, -1, 1
  • -1, -1, -1
  • 1, 1, 1

If force (F), velocity (v) and time (T) are taken as fundamental units, then the dimensions of mass are

  • [FvT-1]

  • [FvT-2]

  • [Fv-1T-1]

  • [Fv-1T]

In an experiment four quantities a, b, c and d are measured with percentage error 1%,2%,3% and 4% respectively. Quantity P is calculated as follows P=a3b2/cd %, Error in P is


  • 14%

  • 10%

  • 7%

  • 4%

The density of material in the CGS system of units is 4g/cm3. In a system of units in which unit of length is 10cm and unit of mass is 100g when the value of density of material in this system will be:

  • 0.4

  • 40

  • 400

  • 0.04 

Which of the following is a units that of force?

  • N m 

  • mN

  • nm 

  • n S

The dimension of 12ε0E2, where ε0 is permittivity of free space and E is electric field, is

(a) ML2T-2                                   (b) ML-1T-2

(c) ML2T-1                                   (d) MLT-1

  • 1
  • 2
  • 3
  • 4

A student measures the distance traversed in free fall of a body, initially at rest in a given time. He uses this data to estimate g, the acceleration due to gravity. If the maximum percentage errors in measurement of the distance and the time are e1 and e2 respectively, the percentage error in the estimation of g is 

  •  e2-e1

  •  e1+2e2

  •  e1+e2 

  •  e1-2e2

0:0:1


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