JEE Questions for Physics Units And Measurements Quiz 2 - MCQExams.com


Physics-Units and Measurements-93047.png
  • M0L0T0
  • M–1L–1T–1
  • M0L2T0
  • M–1L1T2
The respective number of significant figures for the numbers 23.023 , 0.0003 and 2.1×10-3 are
  • 5, 1, 2
  • 5, 1, 5
  • 5, 5, 2
  • 4, 4, 2
A student performed the experiment of determination of focal length of a concave mirror by u-v method using an optical bench of length 1.5 m. The focal length of the mirror used is 24 cm. The maximum error in the location of the image can be 0.2 cm. The 5 sets of ( u, v ) values recorded by the student (in cm) are ( 42, 56), (48, 48), (60, 40), (66, 33), (78, 39). The data sets(s) that cannot come from experiment and is (are) incorrectly recorded, is (are)
  • (42, 56)
  • (48, 48)
  • (66, 33)
  • (78, 40)
In an experiment the angles are required to be measured using an instrument. 29 division of the main scale exactly coincide with the 30 division of the vernier scale. If the smallest division of the main scale is half-a-degree ( = 0.5° ), then the least count of the instrument is
  • one minute
  • half minute
  • one degree
  • half degree
If 3.8×10-6 is added to 4.2×10-5 giving due regard to significant figures, then the result will be
  • 4.58×10-5
  • 4.6×10-5
  • 4.5×10-5
  • None of these
A student has measured the length of a wire equal to 0.04580 m. This value of length has the number of significant figures equal to
  • five
  • four
  • six
  • None of these
A body of mass m = 3.513 kg is moving along the x-axis with a speed of 5.00 ms-1. The magnitude of its momentum is recorded as
  • 17.6 kg ms-1
  • 17.565 kg ms-1
  • 17.56 kg ms-1
  • 17.57 kg ms-1
Two full turns of the circular scale of a screw gauge cover a distance of 1 mm on its main scale. The total number of divisions of 1 mm on its main scale. The total number of divisions on the circular scale is 50. Further, it is found that the screw guage has a zero error of –0.03 mm. While measuring the diameter of a thin wire, a student notes the main scale reading of 3 mm and the number of circular scale divisions in line with the main scale as 35. The diameter of the wire is
  • 3.32 mm
  • 3.73 mm
  • 3.67 mm
  • 3.38 mm
The values of two resistors are R1 = ( 6 ± 0.3 ) KΩ and R2 = ( 10 ± 0.2 ) KΩ. The percentage error in the equivalent resistance when they are connected in parallel is
  • 5.125%
  • 2%
  • 3.125%
  • 7%
  • 10.125%

Physics-Units and Measurements-93052.png
  • 12%
  • 7%
  • 5%
  • 14%
If the length of rod A is ( 3.25 ± 0.01 ) cm and that of B is ( 4.19 ± 0.01 ) cm, then the rod B is longer than rod A by
  • ( 0.94 ± 0.00 ) cm
  • ( 0.94 ± 0.01 ) cm
  • ( 0.94 ± 0.02 ) cm
  • ( 0.94 ± 0.005 ) cm
In a new system of units called star units, 1 kg* =10 kg, 1 m* =1 km and ls* =1min, what will be the value of 1 J in the new system?
  • 2.4 × 10-5 J*
  • 3.6 × 10-4 J*
  • 4.2 × 10-3 J*
  • 4.2 × 10-2 J*
If mass is measured in unit of α kg, length in β m and time in γ s, then calorie would be
  • 4.2 αβ2 γ-2
  • 4.2 α-1β-2 γ2
  • 4.2 α-1β-2 γ-2
  • 4.2 α-2β-2 γ-2

Physics-Units and Measurements-93057.png
  • C-2 Nm2
  • C2 N-1 m-2
  • C2 Nm2
  • C-2 N-1 m-2
1 ns is defined as
  • 10-9 s of Kr–clock of 1650763.73 oscillations
  • 10-9 s of Kr–clock of 6521389.63 oscillations
  • 10-9 s of Cs–clock of 1650763.73 oscillations
  • 10-9 s of Cs–clock of 9192631770 oscillations
If K denotes coefficient of thermal conductivity, d the density and c the specific heat, the unit of X , where X = K/ dc will be
  • cm s -1
  • cm 2 s -2
  • cm s
  • cm 2 s -1

Physics-Units and Measurements-93060.png
  • The unit of λ is same as that of x and A.
  • The unit of λ is same as that of x but not of A.

  • Physics-Units and Measurements-93061.png

  • Physics-Units and Measurements-93062.png
1 Wb/m2 is equal to
  • 104 gauss
  • 4π x 10-3 gauss
  • 102 gauss
  • 10-4 gauss
Density of liquid in CGS system is 0.625 g–cm-3 . What is its magnitude in SI system?
  • 0.625
  • 0.0625
  • 0.00625
  • 625
To find the distance d over which a signal can be seen clearly in foggy conditions, a railway engineer uses dimensional analysis and assumes that the distance depends on the mass density ρ of the fog, intensity (power/area) S of the light from the signal and its frequency f. The engineer finds that d is proportional to S1/n . The value of n
  • 2
  • 3
  • 1
  • 4
If the force is given by F = at + bt2 with t as time. The dimensions of a and b are
  • [MLT-4], [MLT-4]
  • [MLT-3], [MLT-4],
  • [ML2 T-3], [ML2T-2],
  • [ML2 T-3], [ML3 T-4],
The dimensional formula of physical quantity is [Ma Lb Tc ]. Then, that physical quantity is
  • spring constant, if a =1, b = 1, and c = –2
  • surface tension, if a =1, b =1, and c = –2
  • force, if a =1, b =1,c = 2
  • angular frequency, if a = 0, b = 0, c = –1
SI unit of pressure is
  • Pascal
  • Dynes/cm2
  • cm of Hg
  • Atmosphere
The energy (E), angular momentum (L) and universal gravitational constant (G) are chosen as fundamental quantities. The dimensions of universal gravitational constant in the dimensional formula of Planck's constant (h) is
  • zero
  • -1

  • Physics-Units and Measurements-93074.png
  • 1

Physics-Units and Measurements-93076.png
  • time
  • mass
  • length
  • force
Dimensional formula for the universal gravitational consant G is
  • [M -1 L 2T -2 ]
  • [M 0 L 0T 0 ]
  • [M -1 L 3T -2 ]
  • [M -1 L 3T -1 ]
The velocity of a particle v at an instant t is given by v = at + bt2, the dimension of b is
  • [L]
  • [LT -1]
  • [LT -2 ]
  • [LT -3]
In the relation x =cos (ωt + kx), the dimensions of ω are
  • [M0LT ]
  • [M0L -1T0]
  • [M0L 0T-1]
  • [M0LT-1]
The air bubble formed by explosion inside water performed oscillation with time period T that is directly proportional to padb Ec , where p is the pressure, d is the density and E is the energy due to explosion. The values of a, b and c will be
  • –5/6, 1/2, 1/3
  • 5/6, 1/3, 1/2
  • 5/6, 1/2, 1/3
  • None of the these
Dimensional formula for force is
  • [ML2 T -2 ]
  • [MLT -2 ]
  • [ML -1 T -2 ]
  • [ML2 T -3 ]
Dimensions of resistance in an electrical circuit, in terms of dimension of mass M, of length L, of time T and current I, would be
  • [ML2 T -3I -1 ]
  • [ML2 T -2]
  • [ML2 T -1I -1 ]
  • [ML2 T -3I -2]
The speed (v) of ripples on the surface of water depends on surface tension (σ), density (ρ) and wavelength (λ). The square of speed (v2) is proportional to

  • Physics-Units and Measurements-93084.png
  • 2)
    Physics-Units and Measurements-93085.png

  • Physics-Units and Measurements-93086.png

  • Physics-Units and Measurements-93087.png

Physics-Units and Measurements-93089.png
  • [M0 L2 T0 ]
  • [M L2 T ]
  • [ML0 T-1 ]
  • [ML2 T-1 ]

Physics-Units and Measurements-93091.png
  • [L -1 T ]
  • [L 2 T 2 ]
  • [L 2 T -2 ]
  • [LT-1 ]
The dimensions of kinetic energy are
  • [M2 L2 T]
  • [ML2 T]
  • [ML2 T-2 ]
  • [ML2 T -1 ]
The dimensional formula of magnetic flux is
  • [MLT -2 A -1 ]
  • [ML2 T -1 A -1 ]
  • [ML2 T -1 A -2 ]
  • [ML2 T -2 A -1 ]
If force is proportional to square of velocity, then the dimensions of proportionality constant are
  • [ML -1 T ]
  • [ML -1 T0 ]
  • [ MLT0]
  • [ M0 LT -1 ]

Physics-Units and Measurements-93096.png
  • a= [L], b=[LT], c=[T2]
  • a=[L2], b=[T], c=[LT -2]
  • a=[LT 2], b=[LT], c=[L]
  • a=[LT -2], b=[L], c=[T]
The dimensions of Planck's constant are
  • [M2 L2 T -2 ]
  • [M L T -2 ]
  • [M L2 T -2 ]
  • [M L2 T -1 ]
Dimensions of bulk modulus are
  • [M-1 LT-2 ]
  • [ML-1 T-2 ]
  • [ML-2 T-2 ]
  • [M2 L2T-1 ]
Which one of the following represents the correct dimensions of the coefficient of viscosity?
  • [ML-1 T -2 ]
  • [MLT -1 ]
  • [ML-1 T -1 ]
  • [ML-2 T -2 ]
Which of the following units denotes the dimensions [ML2 / Q2] , where Q denotes the electric charge?
  • Wbm -2
  • henry (H)
  • Hm -2
  • Weber (Wb)
Which of the following is dimensionless?

  • Physics-Units and Measurements-93102.png
  • 2)
    Physics-Units and Measurements-93103.png

  • Physics-Units and Measurements-93104.png

  • Physics-Units and Measurements-93105.png
If C, R, L and I denote capacity, resistance, inductance and electric current respectively, the quantities having the same dimensions of time are
Physics-Units and Measurements-93107.png
  • (I) and (II)
  • (I) and (III)
  • (I) and (IV)
  • (I), (II) and (III)
Find the dimensions of electric permittivity
  • [A2 M -1 L -3 T4]
  • [A2 M -1 L -3 T0]
  • [A M -1 L -3 T4]
  • [A2 M 0 L -3 T4]
Which of the following sets have different dimensions?
  • Pressure, young's modulus, stress
  • Emf, potential difference, electric potential
  • Heat, work done, energy
  • Dipole moment, electric flux, electric field
Position of a body with acceleration a is given by x = kam tn . Here, t is time. Find the values of m and n
  • m = 1, n = 1
  • m = 1, n = 2
  • m =2, n = 1
  • m = 2, n = 2
If C is capacitance and q is charge, then the dimension of q2 /C is same as that of
  • work
  • angular momentum
  • force
  • torque and energy
The current voltage relation of diode is given by I = (e1000V/T –mA, where the applied V is in volts and the temperature T is in degree Kelvin. If a student makes an error measuring ±0.01 V while measuring the current of 5 mA at 300K, what will be the error in the value of current in mA ?
  • 0.2 mA
  • 0.02 mA
  • 0.5 mA
  • 0.05 mA

Physics-Units and Measurements-93114.png
  • 4%
  • 3%
  • 11%
  • 1%
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Physics Quiz Questions and Answers