EASY

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The radius of the proton is about $10^{- 15}$ m. The radius of the observable universe is $10^{26}$ m. identify the distance which is half-way between these two extremes on a logarithmic scale.

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Important Questions on Units and Measurements

EASY

Physics>Mechanics>Units and Measurements>Significant Figures

The number of significant figures in

0.07800

EASY

Physics>Mechanics>Units and Measurements>Significant Figures

The distance of a circle is

2.486 m

. Its area with due regard to signifiant figures is (Given

π = 3.142

)

EASY

Physics>Mechanics>Units and Measurements>Significant Figures

A body accelerates from rest with a uniform acceleration

a

for a time

t .

The uncertainty in '

a

' is

8 %

and the uncertainty in '

t

' is

4 % .

The uncertainty in the speed is

MEDIUM

Physics>Mechanics>Units and Measurements>Significant Figures

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

MEDIUM

Physics>Mechanics>Units and Measurements>Significant Figures

For the four sets of three measured physical quantities as given below. Which of the following options is correct?

(i)

A_{1} = 24.36, B_{1} = 0.0724, C_{1} = 256.2

(i i)

A_{2} = 24.44, B_{2} = 16.082, C_{2} = 240.2

(i i i)

A_{3} = 25.2, B_{3} = 19.2812, C_{3} = 236.183

(i v)

A_{4} = 25, B_{4} = 236.191, C_{4} = 19.5

EASY

Physics>Mechanics>Units and Measurements>Significant Figures

N_{A}, N_{B}

and

N_{C}

are the number of significant figures in

A = 0.001204 m, B = 43120000 m

, and

C = 1.200 m

respectively then

EASY

Physics>Mechanics>Units and Measurements>Significant Figures

The area of a rectangular field (in

m^{2}

) of length

55.3 m

and breadth

25 m

after rounding off the value for correct significant digits is:

EASY

Physics>Mechanics>Units and Measurements>Significant Figures

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

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Physics>Mechanics>Units and Measurements>Significant Figures

Taking into account of the significant figures, what is the value of

9.99 m - 0.0099 m

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Physics>Mechanics>Units and Measurements>Significant Figures

The length and diameter of a cylinder are measured to be

10.1031 cm

and

2.0935 cm

respectively. The volume of the cylinder to an appropriate significant figures is

HARD

Physics>Mechanics>Units and Measurements>Significant Figures

There are two vernier calipers both of which have $1 cm$ divided into $10$ equal divisions on the main scale. The Vernier scale of one of the calipers $(C_{1})$ has $10$ equal divisions that correspond to $9$ main scale divisions. The Vernier scale of the other caliper $(C_{2})$ has $10$ equal divisions that correspond to $11$ main scale divisions. The readings of the two calipers are shown in the figure. The measured values (in $cm$ ) by calipers $C_{1}$ and $C_{2}$ respectively, are

Question Image

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Physics>Mechanics>Units and Measurements>Significant Figures

In an experiment on a simple pendulum to determine the acceleration due to gravity, the student measures the length of the thread as

63.2 cm

and diameter of the pendulum bob as

2.256 cm .

The student should take the length of the pendulum to be

HARD

Physics>Mechanics>Units and Measurements>Significant Figures

In an experiment to determine the acceleration due to gravity

g

, the formula used for the time period of a periodic motion is

T = 2 π \sqrt{\frac{7 (R - r)}{5 g}} .

The values of

R

and

r

are measured to be

(60 \pm 1) mm and (10 \pm 1) mm,

respectively. In five successive measurements, the time period is found to be

0.52 s

0.56 s

0.57 s

0.54 s

and

0.59 s

. The least count of the watch used for the measurement of time period is

0.01 s

. Which of the following statements (s) is (are) true?

MEDIUM

Physics>Mechanics>Units and Measurements>Significant Figures

The final result of the sum of the numbers

523.32, 1.21524

and

107.3

rounded to correct significant figures is

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Physics>Mechanics>Units and Measurements>Significant Figures

Diameter of a steel ball is measured using a Vernier calipers which has divisions of 0.1 cm on its main scale (MS) and 10 divisions of its Vernier scale (VS) match 9 divisions on the main scale. Three such measurements for a ball are given as:

S.No.	MS (cm)	VS divisions
1.	0.5	8
2.	0.5	4
3.	0.5	6

If the zero error is - 0.03 cm, then mean corrected diameter is:

MEDIUM

Physics>Mechanics>Units and Measurements>Significant Figures

The percentage errors in quantities

P

Q

R

and

S

are

0.5 %

1 %

3 %

and

1.5 %

respectively in the measurement of a physical quantity

A= \frac{P^{3} Q^{2}}{\sqrt{R} S}

. The maximum percentage error in the value of

A

will be:

HARD

Physics>Mechanics>Units and Measurements>Significant Figures

The current voltage relation of diode is given by I = (e¹⁰⁰⁰^V/T - 1) mA, where the applied voltage V is in volts and the temperature T is in degree Kelvin. If a student makes an error measuring

\pm 0.01 V

while measuring the current of 5 mA at 300 K, what will be the error in the value of current in mA ?

EASY

Physics>Mechanics>Units and Measurements>Significant Figures

Order of magnitude of a physical quantity is the

MEDIUM

Physics>Mechanics>Units and Measurements>Significant Figures

The area of a square is

5.29 c m^{2} .

The area of

7

such squares taking into account the significant figures is:

MEDIUM

Physics>Mechanics>Units and Measurements>Significant Figures

The diameter and height of a cylinder are measured by a meter scale to be

12 .6 \pm 0 .1 cm

and

34 .2 \pm 0 .1 cm

, respectively. What will be the value of its volume in appropriate significant figures?

The radius of the proton is about 10-15m. The radius of the observable universe is 1026m. identify the distance which is half-way between these two extremes on a logarithmic scale.

Important Questions on Units and Measurements

Learn and Prepare for any exam you want !

The radius of the proton is about $10^{- 15}$ m. The radius of the observable universe is $10^{26}$ m. identify the distance which is half-way between these two extremes on a logarithmic scale.