Page 1 - 20. Sci Phy Answer Key 2023 (AK016)
P. 1

Unit 1: Physical Quantities, Units and Measurements             (iii)  0 145 nm =  0 145 10 - 9  m
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              Revision 1                                                        =  14510 ´ 10  m
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                                                                                              9
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              1.  (a)   It is a quantity which can be measured with a           =  14510 - 10  m
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                     measuring instrument.
                 (b)   It  allows  the  measurements  made  in      (iv)  53 Gm =  53 10 9  m
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                     different parts of the world to be uniform and          =  53 10 ´ 10  m
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                                                                                     1
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                     standardised.
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                 (c)   (i)   Length; m   (ii)   kilogram; kg                 =  53 10  m
                     (iii)   Current; ampere                        (v)  0 025ms =  0 025 10  s
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                     (iv)   second; s   (v)   Temperature; kelvin
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                                                                                             3
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                                                                                        2
                 (d)  (i)   It is an efficient way to represent a very small   =  25 10 ´ 10  s
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                         or very large number in the measurement.              =  25 10  s
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                     (ii)    giga        G                          (vi)  8000 kg =  8000 10 3  g
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                             mega        M                                     =´    3  10  g
                                                                                810 ´
                                                                                         3
                             kilo        k
                                                                                810  g
                             deci        d                                     =´    6
                             centi       c
                             milli       m                  Revision 2
                             micro       µ                  1.  (a)   F    [It is metre.]   (b)   T
                             nano        n
                                                                (c)   F  [A  precision  of  0.01cm  is  needed  for  a
                                                                    reading of 2.15 cm.]
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              2.  (a)  (i)  0.50 ÷ 10  = 50 cm
                     (ii)  12.4 ÷ 10  = 12 400 ms           2.  (a)   It is an error due to the position of the observer's
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                                 −6
                     (iii)  0.03 ÷ 10  = 30 000 μg                  eyes  not  vertically  above  the  markings  of  the
                     (iv)  12.5 × 10  ÷ 10  = 0.125 MA              instrument when taking the reading.
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                                      6
                     (v)  3.12 × 10  ÷ 10  = 3.12 × 10  dm      (b)   The ‘0’ marking of the scale is missing/There is
                                       −1
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                     (vi)  125 × 10  ÷ 10  = 1.25 × 10  nm          a gap between the metre rule and the object/
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                                                  6
                                −5
                 (b)  (i)  2.50 × 10  g                             The  object  is  not  placed  exactly  on  the  ‘0’
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                     (ii)  6.01 × 10  = 0.601 g                     marking of the scale
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                     (iii)  0.25 × 10  = 250 m
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                     (iv)  7.15 × 10  × 10  = 7.15 A        3.  (a)   It is the placing of the object not exactly on the
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                                 3
                                                   −8
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                     (v)  0.12 × 10  × 10  = 0.12 × 10  m           ‘0’ marking of the scale.
                     (vi)  832 × 10  × 10  = 832 × 10 −14  g    (b)   (i)   Negative zero error   (ii) Positive zero error
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                                      −9
                 (c)  (i)  6.25 × 10  ÷ 10  = 6.25 × 10  km     (c)   1.8 cm − 0.2 cm =1.6 cm
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                     (ii)  136 × 10  ÷ 10  = 1.36 × 10  mA
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                                                 11
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                     (iii)  1.25 × 10  ÷ 10  = 1.25 × 10  ns  4.  (a)   Measuring tape
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                     (iv)  0.012 × 10  ÷ 10  = 1.2 × 10  cm     (b)   Digital micrometer screw gauge
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                     (v)  2.64 × 10  × 10  ÷ 10                 (c)   Digital calipers            (d)   Metre rule
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                                            3
                         = 2.64 × 10  km                        (e)   Digital calipers
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                     (vi)  0.14 × 10  × 10  ÷ 10
                                      3
                                 6
                                           −3
                         = 1.4 × 10  mm                     5.  X  is  inside  jaws  to  measure  the  internal  length  /
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                                                                diameter of an object
                                                                Y is outside jaws to measure the external length /
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                                                 3
              3  (a)  (i)  4 × 10  m   (ii) 5.6 × 10  s         diameter of an object
                     (iii) 4.12 × 10  J  (iv) 9 × 10  g         Z is tail to measure the depth of an object
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                                                –8
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                     (v)  3.45 × 10  m  (vi) 3.7341 × 10  s
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                 (b) (i)  05 km =  05 10 m                  Revision 3
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                                          3
                               =´    - 1  10  m             1.  (a)   second (s)         (b)  Stopwatch/Digital watch
                                 510 ´
                                 510  m
                               =´    2                      2.  (a)   (i)   It is the time taken for a pendulum to make
                     (ii)  12 s = µ  12 10  s                          one complete oscillation.
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                                           6
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                                      1
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                              =  12 10 ´ 10  s                       (ii)   20 → 16.4 s

                                                                       1 → 0.82 s
                              =  12 10  s                              The period of the pendulum is 0.82 s.
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