Surface tension of water in C . G . S . units is 72 d y n e c m . What is its value in S . I . . units?

Surface tension of water is defined as ratio of force per unit length. It is given in CGS system = 72 dyne / cm . Since 1 dyne = 10 - 5 N 1 c m = 10 - 2 m Now Surface tension in S.I. system is Newton per meter. 1 dyne / cm = 10 - 5 / 10 - 2 = 10 - 3 N / m ∴ 72 dyne / cm = 72 × 10 - 3 N / m

A force ( 5 . 87 ± 0 . 3 ) N is applied on an area ( 2 . 85 ± 0 . 6 ) m 2 . What is pressure on the area?

Here, Force F = 5 . 87 ± 0 . 3 N ∆ F = 0 . 3 N Area A = 2 . 85 ± 0 . 6 m 2 ∆ A = 0 . 6 m 2 The pressure is calculated as : P = F A = 5 . 87 N 2 . 85 m 2 = 2 . 06 Nm - 2 The relative error in the pressure is calculated as : ∆ P P = ∆ F F + ∆ A A = 0 . 3 5 . 87 + 0 . 6 2 . 85 ∆ P = 2 . 06 0 . 261 = 0 . 53 Nm - 2 Therefore, the pressure on that area is 2 . 06 ± 0 . 53 Nm - 2 .

E M B I B E

Bureau's Higher Secondary Physics Class 11>Chapter 1 - Physical World and Measurements>MODEL QUESTIONS

MODEL QUESTIONS

Author:Odisha Board

Odisha Board Physics Solutions for Exercise - MODEL QUESTIONS

Simple step-by-step solutions to MODEL QUESTIONS questions of Physical World and Measurements from Bureau's Higher Secondary Physics Class 11. Also get 3D topic explainers, cheat sheets, and unlimited doubts solving on EMBIBE.

Questions from MODEL QUESTIONS with Hints & Solutions

MEDIUM

11th Odisha Board

IMPORTANT

Bureau's Higher Secondary Physics Class 11>Chapter 1 - Physical World and Measurements>MODEL QUESTIONS>Q 2

Using force $(F)$ length $(L)$ and time $(T)$ as fundamental dimension. Write down the dimension of mass.

MEDIUM

11th Odisha Board

IMPORTANT

Bureau's Higher Secondary Physics Class 11>Chapter 1 - Physical World and Measurements>MODEL QUESTIONS>Q 3

The value of coefficient of viscosity is $12$ in $C . G . S .$ units. What is the value of the same in $SI$ unit?

HARD

11th Odisha Board

IMPORTANT

Bureau's Higher Secondary Physics Class 11>Chapter 1 - Physical World and Measurements>MODEL QUESTIONS>Q 4

Velocity of sound in a gas depend on its pressure and density. Obtain the relation among velocity, pressure and density.

MEDIUM

11th Odisha Board

IMPORTANT

Bureau's Higher Secondary Physics Class 11>Chapter 1 - Physical World and Measurements>MODEL QUESTIONS>Q 5

Surface tension of water in $C . G . S .$ units is $72 \frac{d y n e}{c m}$ . What is its value in $S . I .$ . units?

HARD

11th Odisha Board

IMPORTANT

Bureau's Higher Secondary Physics Class 11>Chapter 1 - Physical World and Measurements>MODEL QUESTIONS>Q 9

In an experiment time period of a simple pendulum are measured as $2.63 s, 2.56 s$ , $2.71 s, 2.80 s$ . Find average absolute error and the percentage error.