An accurate measurement implies that

the closeness of the mean of the readings to the true value

the spread of the readings are broad around the mean value

the spread of the readings are narrow around the mean value

the mean value of the readings is always lower than the true value

the mean value of the readings is always higher than the true value

EASY

NDA & NA EE

IMPORTANT

Earn 100

1 astronomical unit (AU) is the average distance between

50% studentsanswered this correctly

Important Questions on Physical World and Measurement

EASY

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 8

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

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 9

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

1 %

, the error in the measurement of volume will be

EASY

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 10

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

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 11

A physical quantity,

X = \frac{a^{2} b^{2}}{\sqrt{c}}

. if

%

error in

a, b

and

c

are

1 %, 2 %

and

4 %

respectively, then the

%

error in

X

EASY

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 12

The relative error in the determination of the surface area of a sphere is

α

. The relative error in the determination of its volume is

EASY

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 13

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

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 14

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

NDA & NA EE

IMPORTANT

Physics Crash Course NDA & NA EE>Chapter 2 - Physical World and Measurement>Exercise 1>Q 15

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

1 astronomical unit (AU) is the average distance between

Important Questions on Physical World and Measurement

Learn and Prepare for any exam you want !