33 Years NEET-AIPMT Chapterwise Solutions - Physics 2020

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2 NEET-AIPMT Chapterwise Topicwise Solutions Physics
CHAPTER
2
Units and
Measurements
2.2 The International System of Units
1. The unit of thermal conductivity is
(a) W m –1 K –1 (b) J m K –1
(c) J m –1 K –1 (d) W m K –1 (NEET 2019)
2. The damping force on an oscillator is directly
proportional to the velocity. The units of the constant
of proportionality are
(a) kg m s –1 (b) kg m s –2
(c) kg s –1 (d) kg s (2012)
3. The unit of permittivity of free space, e 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)
2.6 Accuracy, Precision of Instruments and
Errors in Measurement
4. A screw gauge has least count of 0.01 mm and there
are 50 divisions in its circular scale. The pitch of the
screw gauge is
(a) 0.01 mm (b) 0.25 mm
(c) 0.5 mm (d) 1.0 mm (NEET 2020)
5. In an experiment, the percentage of error occurred
in the measurement of physical quantities A, B, C
and D are 1%, 2%, 3% and 4% respectively. Then the
maximum percentage of error in the measurement
X, where X AB 2 1/
2
= , will be
13 / 3
C D
(a) 10% (b) (3/13)%
(c) 16% (d) –10% (NEET 2019)
6. The main scale of a vernier callipers has
n divisions/cm. n divisions of the vernier scale
coincide with (n – 1) divisions of main scale. The
least count of the vernier callipers is
1
(a)
cm (b) 1
( n+ 1)( n−1)
n cm
1
(c)
2
n cm 1
(d) cm
nn ( + 1)
(Odisha NEET 2019)
7. A student measured the diameter of a small steel
ball using a screw gauge of least count 0.001 cm.
The main scale reading is 5 mm and zero of circular
scale division coincides with 25 divisions above the
reference level. If screw gauge has a zero error of
–0.004 cm, the correct diameter of the ball is
(a) 0.521 cm (b) 0.525 cm
(c) 0.053 cm (d) 0.529 cm (NEET 2018)
8. 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
3 2
ab
P =
cd
. % error in P is
(a) 7% (b) 4% (c) 14% (d) 10%
(NEET 2013)
9. 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 e 1 and e 2 respectively,
the percentage error in the estimation of g is
(a) e 2 – e 1 (b) e 1 + 2e 2
(c) e 1 + e 2 (d) e 1 – 2e 2 (Mains 2010)
10. 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% (2008)
11. 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)
12. 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)