## NEET AIPMT Physics Chapter Wise Solutions – Units and Measurements

NEET AIPMT Physics Chapter Wise SolutionsChemistryBiology

**1. If dimensions of critical velocity v**_{c }**of a liquid flowing through a tube are expressed as [η ^{x}ρ^{y}r^{z}] where η, ρ and r are the coefficient of viscosity of liquid, density of liquid and radius of the tube respectively then the values of x, y and z are given by**

(a) -1,-1,-1

(b) 1,1,1

(c) 1,-1,-1

(d) -1,-1, 1

**(AIPMT 2015)**

**2. If energy (E), velocity (V) and time (T) are chosen as the fundamental quantities, the dimensional formula of surface tension will be
**(a) [EV

^{-2}T

^{-2}]

(b) [E

^{-2}V

^{-1}T

^{-3}]

(c) [EV

^{-2}T

^{-1}]

(d) [EV

^{-1}T

^{-2}]

**(AIPMT 2015, Cancelled)**

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

(a) [FVT^{-1}]

(b) [FVT^{-2}]

(c) [FV^{-1}T^{-1}]

(d) [FV^{-1}T] **(AIPMT 2014)**

**4. 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
**

**% error in P is**

(a) 7%

(b) 4%

(c) 14%

(d) 10%

**(NEET 2013)**

**5. The pair of quantities having same dimensions is**

(a) Impulse and Surface Tension

(b) Angular momentum and Work

(c) Work and Torque

(d) Young’s modulus and Energy **( Karnataka NEET 2013)**

**6. The damping force on an oscillator is directly proportional to the velocity. The units of the constant of proportionality are**

(a) kg ms^{-1}

(b) kgms^{-2}

(c) kg s^{-1}

(d) kg s **(Prelims 2012)**

**7. The dimensions of are ( μ _{0}ε_{0} )^{-2} are**

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

(a) 0.04

(b) 0.4

(c) 40

(d) 400

**(Mains 2011)**

**9. The dimension of ε _{0}E^{2} , where e0 is permittivity of free space and E is electric field is**

(a) ML

^{2}T

^{-2}

(b) ML

^{-1}T

^{-2}

(c) ML

^{2}T

^{-1}

(d) MLT

^{-1 }

**(Prelims 2010)**

**10. 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 e _{2 }respectively, the percentage error in the estimation of g is**

(a) e

_{2}-e1

(b) e1 + 2e

_{2}

(c) e1+ e

_{2}

(d) e1-2e

_{2}

**(Mains 2010)**

**11. If the dimensions of a physical quantity are given by _{M}^{a}_{L}^{b}_{T}^{c}, then the physical quantity will be**

(a) velocity if a = l,b = 0,c =- 1

(b) acceleration if a = 1, h = l,c = -2

(c) force if a = 0, b = – 1, c = – 2

(d) pressure if a = 1, b = – 1, c= -2

**(Prelims 2009)**

**12. If the error in the measurement of radius of a sphere is 2%, then the error in the determination of volume of the sphere will be**

(a) 8%

(b) 2%

(c) 4%

(d) 6%** (Prelims 2008)**

**13. Which two of the following five physical parameters have the same dimensions ?**

1. energy density

2. refractive index

3. dielectric constant

4. Young’s modulus

5. magnetic field

(a) 1 and 4

(b) 1 and 5

(c) 2 and 4

(d) 3 and 5** (Prelims 2008)**

**14. Dimensions of resistance in an electrical circuit, in terms of dimension of mass M, of length L, of time T and of current I, would be**

(a) [ML^{2}T^{-2}]

(b) [ML^{2}T^{-1}I^{-1}^{ }]

(c) [ML^{2}T^{-3}I^{-2}]

(d) [ML^{2}T^{-3}I^{-1}] **(2007)**

**15. The velocity v of a particle at time t is given by V=at+ where a, b and c are constants. ****The dimensions of a, b and c are**

(a) [L], [LT] and [LT^{-2}]

(b) [LT^{-2}], [L] and [T]

(c) [L^{2}], [T] and [LT^{-2}]

(d) [LT^{-2}], [LT] and [L]. (**2006)**

**16. The ratio of the dimensions of Planck constant and that of moment of inertia is the dimensions of**

(a) time

(b) frequency

(c) angular momentum

(d) velocity. **(2005)**

**17. The dimensions of universal gravitational constant are**

(a) [M^{-1}L^{3}T^{-2}]

(b) [ML^{2}T^{-1}]

(c) [M^{-2}L^{3}T^{-2}]

(d) [M^{-2}L^{2}T^{-1}] **(2004,1992)**

**18. The unit of permittivity of free space, ε _{0}, is**

(a) coulomb/newton-metre

(b) newton-metre

^{2}/coulomb

^{2}

(c) coulomb

^{2}/newton-metre

^{2}

(d) coulomb

^{2}/(newton-metre)

^{2}

**(2004)**

**19. The dimensions of Planck constant equals to that of**

(a) energy

(b) momentum

(c) angular momentum

(d) power.** (2001)**

**20. Which pair do not have equal dimensions ?**

(a) Energy and torque

(b) Force and impulse

(c) Angular momentum and Planck constant

(d) Elastic modulus and pressure. **(2000)**

**21. The dimensional formula of magnetic flux is**

(a) [M^{0}L^{-2}T^{-2}A^{-2}]

(b) ML^{0}T^{-2}A^{-2}]

(c) [ML^{2}T^{-2}A^{-1}]

(d) [ML^{2}T^{-1}A3] **(1999)**

**22. An equation is given here(=)where P = Pressure, V = Volume and 0 = Absolute temperature. If a and b are constants, the dimensions of a will be**

(a) [ML^{-5}5T^{-1}]

(b) [ML^{5}T^{1}]

(c) [ML^{5}T^{-2}]

(d) [M^{-1}L^{5}T^{2}]. (**1996)**

**23. 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 lengths are 3% and 2% respectively, the maximum error in the measurement of density would be**

(a) 12%

(b) 14%

(c) 7%

(d) 9%. **(1996)**

**24. The dimensions of impulse are equal to that of**

(a) pressure

(b) linear momentum

(c) force

(d) angular momentum. **(1996)**

**25. Which of the following dimensions will be the same as that of time?
**(a)

(b)

(c) LC

(d) .

**(1996)**

**26. Which of the following is a dimensional constant?**

(a) Relative density

(b) Gravitational constant

(c) Refractive index

(d) Poisson ratio.** (1995)**

**27. The dimensions of RC is**

(a) square of time

(b) square of inverse time

(c) time

(d) inverse time. **(1995)**

**28. Percentage errors in the measurement of mass and speed are 2% and 3% respectively. The error in the estimate of kinetic energy obtained by measuring mass and speed will be**

(a) 8%

(b) 2%

(c) 12%

(d) 10%.** (1995)**

**29. Which of the following has the dimensions of pressure?**

(a) [MLT^{-2}]

(b) [ML^{-1}T^{-2}]

(c) [ML^{-2}T^{-2}]

(d) [M^{-1}L^{-1}]. **(1994, 90)**

**30. Turpentine oil is flowing through a tube of length l and radius r. The pressure difference between the two ends of the tube is P. The viscosity of oil is given by η= where v is the ****velocity of oil at a distance x from the axis of the tube. The dimensions of η are**

(a) [M^{0}L^{0}T^{0}]

(b) [MLT^{-1}]

(c) [ML^{2}T^{-2}]

(d) [ML^{-1}T^{-1}] **(1993)**

**31. The time dependence of a physical quantity p is given by p = p0 exp (-a/2), where a is a constant and t is the time. The constant a **

(a) is dimensionless

(b) has dimensions [T^{-2}]

(c) has dimensions [T^{2}]

(d) has dimensions of p **(1993)**

**32. P represents radiation pressure, c represents speed of light and S represents radiation energy striking per unit area per sec. The non zero integers x, y, z such that P ^{x}S^{y}c^{z} is dimensionless are**

(a) x= l,y= l,z = 1

(b)x = -l,y=l,z=l

(c) x = l,y = -1, z = 1

(d) x = l,y = 1, z = -1

**(1992)**

**33. A certain body weighs 22.42 g and has a measured ****volume of 4.7cc. The possible error in the measurement of mass and volume are 0.01 g and 0.1 cc. Then maximum error in the densiy will be**

(a) 22%

(b) 2%

(c) 0.2%

(d) 0.02%. **(1991)**

**34. The dimensional formula of permeability of free space μo is**

(a) [MLT^{-2}A^{-2}]

(b) [M^{0}L^{1}T]

(c) [M^{0}L^{2}T^{-1}A^{2}]

(d) none of these.** (1991)**

**35. The frequency of vibration/of a mass m suspended from a spring of spring constant k is given by a relation / = amxky, where a is a dimensionless constant. The values of x and y are**

(a) X= , Y=

(b) X= , Y=

(c)X= , Y=

(d) X= ,Y=**(1990)**

**36. According to Newton, the viscous force acting between liquid layers of area A and velocity gradient Δv/ΔZ is given by F =-ηA , where is constant called coefficient of viscosity. The dimensional formula of q is**

**37. If x = at + bt2, where x is the distance travelled by the body in kilometers while t is the time in seconds, then the units of h is**

(a) km/s

(b) kms

(c) km/s2

(d) kms2. **(1989)**

**38. 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

(d) Angular momentum. **(1989)**

**39. Dimensional formula of self inductance is**

**40. The dimensional formula of torque is**

**41. If C and R denote capacitance and resistance, the dimensional formula of CR is**

(a) [M^{0}L^{0}T^{1}]

(b) [M^{0}L^{0}T^{0}]

(c) [M^{0}L^{0}T^{-1}]

(d) not expressible in terms of MLT. **(1988)**

**42. The dimensional formula of angular momentum is**

**Explanations**