Question #ad131

2 Answers
Oct 30, 2016

1..6

Explanation:

wikipedia
Operation of specific gravity meter is based on Archimedes' principle.
It states that when a solid body is suspended in a fluid it experiences an upward force which is equal to the weight of the fluid displaced by the submerged part of the body.

The depth is read off the scale, as shown in the figure below:
wikipedia

When submerged to the marking 1.0, it corresponds to fluid being water at 4C and 1 atm of pressure.

The position of the marking of 1.0 is not clear from the statement of the problem. As such if the tube sinks in the sample to a point above the mark, the specific gravity of the sample is lower than the that of water and vice-versa.

Assuming that the 1.0 mark is placed at the 10cm length of tube.
Let A be the area of cross-section of the tube.
Its volume which is also Volume of water displaced V=0.1A
As the tube is in equilibrium (upwards thrust=downwards weight)
Weight of tube =Weight of the water displaced
Weight of tube =0.1×A×1000g
where g is acceleration due to gravity.

Now the meter floats with 6cm of its length submerged in the liquid whose density is d and is in equilibrium,
Weight of the liquid displaced = Weight of tube
0.06×A×dg=0.1×A×1000g
0.06×d1000=0.1
We know that SG=ddwater, therefore we get
SGliquid=0.10.06=1..6

Oct 30, 2016

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Explanation:

We know that the density of water at 4C is 1000kgm3or1gcm3.So specific gravity of water will be 1.0.

The given uniform tube of length 10cm has also sp.gravity 1.0.

If the area of cross section of the tube be Acm2 then its volume will be 10Acm3

And its weight becomes =10A×1×g dyne.
where gAcceleration due to gravity

If it floats in water immersing x cm length in water,then weight of water displaced by it will be =xA1g dyne

By Archimedes principle

xAg=10Ag

So x=10cm Hence it floats in water submerged.

Again it floats in the given liquid keeping 6cm immersed.

So the weight of displaced liquid will be=6Aρg dyne
,where ρ is the sp.gravity of the liquid.

Now applying Archimedes principle we have

6Aρg=10A1g

ρ=1061.67