PHYSICS - UNITS AND MEASUREMENTS
By Vijaya Khanduri
Science is based on measurements. Measures were standardised so that a scientists anywhere could understand and use his predecessor's arguments and proofs.
1. The S.I. unit of pressure is
atmosphere
bar
ton
pascal
2. Which of the following is not the basic unit of measurement?
radian
kelvin
mole
candela
3. Which of the following physical quantities has the same dimensional formula as momentum?
force
pressure
impulse
angular momentum
4. 'Parsec' is a unit for measuring
astronomical distances
very small distances
the time
the arc of a circle
5. The unit of surface tension is
newton
newton metre
newton per metre
newton per square metre
6. One Angstrom is equal to
10^-8m
10^-10m
10^8m
10^10m
7. Which, among the following, is not the unit of force?
dyne
sthene
stilb
8. One degree is equal to
pie/360 rad
pie/180 rad
pie/ 90 rad
pie/60 rad
9. 'Ohm' is not the unit of which of the following quantities?
Reluctance
Reactance
Resistance
Impedance
10. 'Lux' is the unit of
luminance
luminous intensity
luminous flux
illumination
11. The dimensional formula for energy is
M L T ^-1
M L^2T^-2
M L^-1T^-2
M L T ^ -2
12. One light-year is equal to
5.8785 x 1012 miles
9.4607 x 1015 metres
0.307 parsec
all the above
13. Unit of pressure used in vacuum technology is
mmHg
millibar
torr
aim
14. Unit of time equal to the period of roatation of earth is
day
solar day
mean solar day
sidreal day
15. The S.I. unit of magnetic field strength is
gilber
oersted
gauss
ampere per metre
16. One litre is not equivalent to
10^6 X mm^3
10^3 X cm^3
10^-3 X m^3
1 X dm^3
17. Which, among the following, is the smallest unit of length?
Angstrom
Fermi
Micron
Nanometre
18. Which of the following does not represent the unit of mutual conductance?
Siemens
mho
ohm^-1
ohm/m
19. Which of the following pairs does not have the same dimension?
Impulse; linear momentum
force; surface tension
stress; pressure
frequency; angular velocity
20. 'Becquerel' is the unit to measure
activity of a radionuclide
absorbed dose
illuminance
specific energy imparted
21. Unit of magnetic flux density is
weber
maxwell
tesla
22. The c.g.s. unit of kinematic viscosity is
poise
stokes
slug
newton per metre square
23. Nit is the unit of
luminous energy
24. Unit of acoustic absorption is
sone
phon
skot
sabin
25. 'Magnitude' is a measure of
direction
stellar brightness
enthalpy
entropy
26. The S.I. unit of electric field strength is
volt per metre
joule per metre
27. The reciprocal of the impedance of an electric current is
conductance
susceptance
admittance
reactance
28.
work
power
stress
torque
29. Which of the following system of units was replaced by S.I. units in 1954?
C.G.S. units
F.P.S. units
M.K.S. units
GIORGI units
30. A logarithmic unit expressing the ratio of power, volatge, current, or sound intensity is known as
neper
bel
noy
nox
31. The unit of frequency is 'hertz'. What is the name given to the unit of frequency equal to 1012 Hz?
fresnel
lloyd
planck
young
32. 'Gal' is a measure of acceleration due to gravity. It is equal to
1 nm/s^2
1 mm/s^2
1 cm/s^2
1 m/s^2
33. 'Bam' is a unit of area for measuring the cross-section of nuclei. It is equivalent to
10^-24 X mm^2
10^24 X cm^2
10^-24 X dm^2
10^24 X m^2
34. The S.I. unit of dose equivalent is
becquerel
curie
gray
sievert
35. Which of the following unite is not used in the area of ionizing radiation?
rent
rod
roentgen
36. A measure of contrast in image reproduction is called
phot
gamma
Talbot
37. 'Rem', the unit dose of ionizing radiation, is an acronym where 'r' stands for 'roentgen', 'e' stands for 'equivalent'. What does 'm' stand for?
'measure'
'man'
'mass'
'metre'
38. Unit of 'luminance' equal to 10000 cd/m2 of a surface is called
lux
39. Unit of subjective pitch in sound is
mel
mil
cycle per second
hertz
40.
erlang
watt
jansky
lambcrt