Subjects
PRICING
COURSES
Start Free Trial
Devisree K.
Online Tutor for past 4 years
Tutor Satisfaction Guarantee
Organic Chemistry
TutorMe
Question:

Lassaigne's test is not shown by diazonium salts and hydrazines( $$NH_2NH_2$$). Why?

Devisree K.

Diazonium salts usually lose N_2 on heating much before they react with fused Na metal. That is why they do not give the above test. Hydrazine does not have C atoms, so it does not form NaCN and hence does not give a positive test for N. In order to test the presence of N in such compounds, during fusion with Na, some charcoal or preferably starch (which contains C but not N,S, halogens, etc.) is added. Under these conditions, C of starch or charcoal combines with N of the compound to form NaCN which give a positive test for N.

MATLAB
TutorMe
Question:

How to import a data file in MATLAB?

Devisree K.

MATLAB incorporates a good interface for importing different types of data files, both through GUI and the command line. the easiest way to import data from a file is to invoke wizard by either (i) selecting IMPORT DATA from the FILE menu of the MATLAB window or (ii) typing uiimport on the command line and then following the instructions on the screen. The import wizard does an excellent job of recognizing most file formats used for text data, spreadsheet data(.xls, .wkl), movie data (.avi),image data (.tiff,.jpef,.png etc.), and audio data (.wav,.au). Alternatively , you can also import data from the file using built-in function importdata(filename) from the command line. The file name must include the file extension so that importdata can understand the file format

Mechanical Engineering
TutorMe
Question:

Explain what do you mean by Intensity of Gravitational Field?

Devisree K.

The intensity of gravitational field of a body at a point in the field is defined as the force experienced by a body of unit mass placed at that point provided the presence of unit mass does not disturb the original gravitational field. It is always directed towards the center of gravity of the body whose gravitational field at a point is a vector quantity and is denoted by $$\vec{E}$$. Let M be the mass of a body with center of gravity at O. Let F be the gravitational force of attraction experienced by a test mass $$m_0$$ when placed at P in the gravitational field of the body, such that OP=x. Now, According to Newtons law of gravitation, F=$$\frac{MGm_0}{x^2}$$ Intensity of gravitational field at P will be $$E=\frac{F}{m_0}=\frac{\frac{MGm_0}{x^2}}{m_0}=\frac{GM}{x^2}$$ in vector form, $$\vec{E} =-\frac{Gm}{x^2}\hat{x}$$ Here negative sign shows that the gravitational intensity is of attractive force. We note that as increases, E decreases and when x= $$\infty$$, E=0. It means that the intensity of gravitational field is zero only at infinite distance from the body. If the test mass is free to move at P,it will be accelerated due to force of attraction F, by the body of mass $$m_0$$. Let a be the acceleration produced in the test mass due to force F, then, F=$$m_0$$a or $$\frac{F}{m_0}$$=a from this, E=a It means that the intensity of gravitational field at a point in the gravitational field is equal to the acceleration of test mass placed at that point. If the gravitational field is due to earth and point P lies on the surface of the earth then , x=R. Now, E=$$\frac{GM}{R^2} =g$$ where g is the acceleration due to gravity at the surface of earth.

Send a message explaining your
needs and DEVISREE will reply soon.
Contact DEVISREE