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Questions Related to physics

A rectangular vessel $ 1 m \times 0.6 m \times 0.5 m $ filled with maize grains. Treat the grains spheres of diameter 0.3 cm each.The number of grains in the vessel is the nearest to 

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. $ 5 \times 10^7 $

  2. $ 1 \times 10^7 $

  3. $ 2 \times 10^7 $

  4. $ 2 \times 10^5 $

Show answer
Correct Option: C
Explanation:

Let n number of grains are in the vessel.

So, volume of cuboid vessel is equal to n times volume of spheres. i.e.

$ 1\times 0.6\times 0.5=n\left( \dfrac{4}{3}\times 3.14\times {{\left( \dfrac{3}{2000} \right)}^{3}} \right) $

$ 0.3=n\dfrac{4}{3}\times 3.14\times 3.375\times {{10}^{-9}} $

$ 0.3=n\times 14.13\times {{10}^{-9}} $

$ n=\dfrac{0.3}{14.13\times {{10}^{-9}}} $

$ n=0.021\times {{10}^{9}}\, $

$ n=2\times {{10}^{7}}$

A single sheet of aluminium foil is folded twice to produce a stack of four sheets. The total thickness of the stack of sheets is measured to be $(0.80\pm 0.02)mm$. This measurement is made using a digital caliper with a zero error or $(-0.20\pm 0.02)mm$
What is the percentage uncertaintyin calculated thickness of a single sheet?
physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. $1.0$%

  2. $2.0$%

  3. $4.0$%

  4. $6.7$%

Show answer
Correct Option: C
Explanation:

The zero error (−0.20) can be removed but its uncertainty (± 0.02) must be added to the measurement uncertainty.

True value of total thickness =$ 0.80 + 0.20 = 1.0 mm  $

Total uncertainty in measurement = $(0.02+0.02)=0.04\ mm$

So the four sheets have a true thickness of $ (1.00 ± 0.04) mm.$
 A single sheet would have a thickness of $(0.25 ± 0.01) mm.$

Percentage error= $\dfrac{0.01}{0.25}\times 100 = 4.0$%

What is the S.I. unit of volume ? How is it related to litre ?

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. $m^3, 1 \ m^3 = 1000$ litre

  2. $cm^3, 1 \ cm^3 = 10^{-3}$ litre

  3. $m^3, 1 \ m^3 = 10^6$ litre

  4. None of the above

Show answer
Correct Option: A
Explanation:

S.I. unit of volume is $m^3$. 

$1m^3=1000\ litre$

Volume of a single liquid drop can be measured using :

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. Burette

  2. Pipette

  3. Flask

  4. Measuring cone

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Correct Option: A
Explanation:

A Burette  is a device used in analytical chemistry for the dispensing of variable, measured amounts of a chemical solution. A volumetric burette delivers measured volumes of liquid.

1 litre is equal to

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. $10^3\,cm^3$

  2. $10\,dm^3$

  3. $10^{-3}\,cm^3$

  4. all the above

Show answer
Correct Option: A
Explanation:

We know that $1$ litre $=10^3 cm^3$

$1 cm=10^{-1} dm$ or $1 cm^3=10^{-3} dm^3$
So, $10^3 cm^3=10^3\times 10^{-3} dm^3=1 dm^3$
Hence, 1 litre $=1 dm^3$
Thus, option A will be correct. 

State whether true or false.

A measuring jar is graduated in ml from bottom to top.

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. True

  2. False

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Correct Option: A
Explanation:

The given statement is true that the measuring jar is graduated in ml from bottom to top.

The volume of water in a measuring cylinder is 55 mL When a stone tied to a string is immersed in the water the water level rises to 83 mL. Find the volume of the stone

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. $28ml^2$

  2. $28ml$

  3. $38ml$

  4. $28m^2l$

Show answer
Correct Option: B
Explanation:
Initial level of water  $v _i = 55 \ ml$
Final level of water  $v _f = 83  ml$
Volume of stone  $V _{stone} = V _f - V _i = 83 - 55 = 28 \ ml$

 In a given system of units, the ratio of unit of volume to that of its area gives 

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. Density

  2. Length

  3. Mass

  4. Decibel

Show answer
Correct Option: B
Explanation:

SI Unit of volume is $m^3$ 

Unit of area is $m^2$
So $\dfrac{Volume}{area}=m^3/m^2=m$, that's the unit of length 

A cubic metre of water at $0^o$C is solidified into ice, density of ice is $0.96$ of water at $0^o$C. Which of the following deductions are true?
$1$. Water expands when solidified.
$2$. Ice will float in water at $0^o$C with half its volume above the surface.
$3$. Density of all liquids are higher than its density when solidified.

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. $3$ only

  2. $2$ only

  3. $1$ only

  4. $1$ and $2$

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Correct Option: C

A cubical block of wood of specific gravity $0.5$ and a chunk of concrete of specific gravity $2.5$ are fastened together. The ratio of mass of wood to the mass of concert which makes the combination to float with its entire volume submerged in water is 

physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

  1. $1/5$

  2. $1/3$

  3. $3/5$

  4. $2/5$

Show answer
Correct Option: A