EASY

Earn 100

Which of the following are correct statements?

(a) Precision refers to the closeness of various measurements for the same quantity.

(b) Accuracy is the agreement of particular values to the true value of the result.

(c) Accuracy is the closeness of various measurements for the same quantity.

50% studentsanswered this correctly

Important Questions on Units and Measurements

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

A student measuring the diameter of a pencil of circular cross-section with the help of a vernier scale records the following four readings

5.50 mm

5.55 mm

5.34 mm

5.65 mm

. The average of these four reading is

5.5375 mm

and the standard deviation of the data is

0.07395 mm

. The average diameter of the pencil should therefore be recorded as :

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

In the density measurement of a cube, the mass and edge length are measured as

(10.00 \pm 0.10) k g

and

(0.10 \pm 0.01) m,

respectively. The error in the measurement of density is:

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

Using screw gauge of pitch

0.1 cm

and

50

divisions on its circular scale, the thickness of an object is measured. It should correctly be recorded as,

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

Time intervals measured by a clock give the following readings: $1.25 s, 1.24 s, 1.27 s, 1.21 s$ and $1.28 s$ . What is the percentage relative error of the observations?

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it ?

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

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:

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

A simple pendulum is being used to determine the value of gravitational acceleration

g

at a certain place. The length of the pendulum is

25.0 c m

and a stopwatch with

1 s

resolution measures the time taken for

40

oscillations to be

50 s

. The accuracy in

g

is:

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

If the error in the measurement of radius of a sphere is

1 %

, the error in the measurement of volume will be

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

A physical quantity $P$ is described by the relation $P = a^{\frac{1}{2}} b^{2} c^{3} d^{- 4}$ . If the relative errors in the measurement of $a$ , $b$ , $c$ and $d$ respectively, are $2 %$ , $1 %$ , $3 %$ and $5 %$ . Then the relative error in $P$ will be:

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

An experiment is performed to obtain the value of acceleration due to gravity g by using a simple pendulum of length L. In this experiment time for 100 oscillations is measured by using a watch of 1 second least count and the value is 90.0 seconds. The length L is measured by using a meter scale of least count 1 mm and the value is 20.0 cm. The error in the determination of g would be :

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

A cylindrical wire has a mass

(0.3 \pm 0.003) g

, radius

(0.5 \pm 0.005) mm

and length

(6 \pm 0.06) cm

. The maximum percentage error in the measurement of its density is

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

An accurate measurement implies that

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

N

divisions on the main scale of a vernier calipers coincide with

(N + 1)

divisions of the vernier scale. If each division of main scale is

a

units, then the least count of the calipers is

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

A physical quantity z depends on four observables

a, b, c

and

d

, as

z = \frac{a^{2} b^{\frac{2}{3}}}{\sqrt{c} d^{3}} .

The percentage of error in the measurement of

a, b, c

and

d

are

2 %, 1.5 %, 4 %

and

2.5 %

respectively. The percentage of error in

z

is :

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

The resistance

R = \frac{V}{I}

where,

V = (100 \pm 5) V

and

I = (10 \pm 0.2) A .

The percentage error in

R

is:

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

The time period of a simple pendulum is given by

T = 2 π \sqrt{\frac{l}{g}} .

The measured value of the length of the pendulum is

10 cm

known to a

1 mm

accuracy. The time for

200

oscillations of the pendulum is found to be

100

second using a clock of

1 s

resolution. The percentage accuracy in the determination of

g

using this pendulum is

x .

The value of

x

to the nearest integer is:-

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

The period of oscillation of a simple pendulum is

T = 2 π \sqrt{\frac{L}{g}} .

Measured value of

L

1.0 m

from meter scale having a minimum division of

1 mm

and time of one complete oscillation is

1.95 s

measured from stopwatch of

0.01 s

resolution. The percentage error in the determination of

' g'

will be:

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

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 = \frac{A^{2} B^{\frac{1}{2}}}{C^{\frac{1}{3}} D^{3}}

will be

EASY

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

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 division of the circular scale coincides with

25

divisions above the reference level. If the screw gauge has a zero error of

- 0.004 cm .

the correct diameter of the ball is__________

MEDIUM

Physics>Mechanics>Units and Measurements>Accuracy and Precision of Instruments

The period of oscillation of a simple pendulum is

T = 2 π \sqrt{\frac{l}{g}} .

Measured value of

l

20.0 cm

, known to

1 mm

accuracy and time for

100

oscillations of the pendulum is found to be

90 s

using a wristwatch of

1 s

resolution. The accuracy in the determination of

g

Which of the following are correct statements? (a) Precision refers to the closeness of various measurements for the same quantity. (b) Accuracy is the agreement of particular values to the true value of the result. (c) Accuracy is the closeness of various measurements for the same quantity.

Important Questions on Units and Measurements

Learn and Prepare for any exam you want !

Which of the following are correct statements?

(a) Precision refers to the closeness of various measurements for the same quantity.

(b) Accuracy is the agreement of particular values to the true value of the result.

(c) Accuracy is the closeness of various measurements for the same quantity.