IIT JEE Physics Coaching Made easy
How Measurement Analysis can be used to Solve IIT-JEE Physics..??
Physics describes the laws of nature. Observations and measurement form the
backbone of physics. In order to consider the importance of measurements,
let us consider the following example:
(1) Consider that a force is applied on a body to move it. The force produces
some acceleration in the motion of the body. The question is how much acceleration
is produced in the motion of the body. This can be known only if one measures
the magnitude of the applied force and the mass of the body.
(2) Consider a projectile, motion of a body which falls to a place ahead of
us by covering some distance. Now the question is how much distance is covered
by the body. The distance covered by the body can be known by measuring the
initial speed of the body, time taken by the body to cover the distance and
the acceleration of the body in the motion of the body.
(3) The fever of a person can only be known only by measuring the temperature
of the body.
“It is generally seen that IIT-JEE Paper that is conducted by the Govt.
of India to the entry to the most premiere Engineering institutes across India
gives a few questions that can be directly done by cross checking and evaluating
the options dimensionally. If the Student uses presence of mind, a bit of
concept and dimensions then a few questions can be done like that without
even trying to calculate the Answer. For Example, A ball thrown with velocity
“v”, With an acceleration “A” with the horizontal,
passing the “N” stairs in time “T” and then obviously
the Option given for the Angle with which it strikes the ground can be given
by (NV/AT) and not by (NA/VT) or by (NT/AV) because the an Angle is always
a dimension less quantity… So only the Option that says (NV/AT) is dimensionless
so it can be the only possible option, Hence the Above question was be able
to be done without even using any equation of Motions or any Concept or calculations.
“
– IIT-JEE, AIR – 243, 2009
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Lets take another example in order to understand this case better. Say for Example the question says that a pendulum is dipped in a mixture of oil and water with different densities. Now the options have different forms of answer. Obviously in this case the density of the oil is less than water that mean that if the quantity of oil will be more, then the time period will be more and as the water keeps on increasing then the time period keeps on decreasing. Also obviously this is so very sure is that no matter what the answer is, it has to have a unit of seconds.So in case a student is unable to do the question still manages to atleast calculate the dimensions of the given options then he will be able to eliminate atleast 2 options, the he can choose from the rest 2 options. Following this a lot More questions can be done easily.
Therefore, to know and to understand a physical situation completely, one has to measure the quantity and do the dimensional analysis.
We hope the above write up was helpful to all the students preparing for IIT-JEE
and are about to write the exam this year.
Best of luck from Excel IIT Coaching Classes.