Tag: archimedes' principle

Questions Related to archimedes' principle

A rectangular block is $10\ cm \times 10\ cm \times 15\ cm$ in size is floating in water with $10\ cm$ side vertical. If it floats with $15\ cm$ side vertical, then the level of water will

  1. $Rise$

  2. $Fall$

  3. $Remain\ same$

  4. $Change\ according\ to\ density\ of\ block$


Correct Option: C

A boat having some iron pieces is floating in a pond. If iron pieces are thrown in the liquid then level of liquid 

  1. Increases

  2. Decreases

  3. May increase or decrease

  4. Neither increases nor decreases


Correct Option: B

A coil of wire of cross-section$0.50$ $m m ^ { 2 }4$ weighs $75g$ in air and $65g$ in water. The length of the coil in cm is

  1. $\frac { 10 ^ { 2 } } { 50 }$

  2. $\frac { 10 ^ { 2 } } { 0.50 }$

  3. $\frac { 10 ^ { 5 } } { 50 }$

  4. $\frac { 10 ^ { 5 } } { 0.0050 }$


Correct Option: C

A hollow metal container floats in water, because it displaces _____ weight of water than/as its own weight.

  1. more

  2. less

  3. same

  4. can't say


Correct Option: C
Explanation:

FALSE
If hollow metal container  displaces more weight of water than its own weight it will sink.
Because, we know that by Archimedes principle, the weight of water displaced should be equal to the weight of the part submerged in water. If the weight is greater than the weight of the object, it will sink.

A piece of ice floats in a liquid denser than water.The liquid fills the vessel upto the edge. If ice melts completely then:

  1. water level remains unchanged

  2. water level decreases

  3. water overflows

  4. data is insufficient


Correct Option: C
Explanation:

Density of ice is less than that of water. If it melts it becomes water. But still, the density of liquid is greater than water therefore, water remains on top and thus it floats and then overflows.

State whether the given statement is True or False :

When submerged, a $3N$ block appears to weigh only $1N$. The missing weight is equal to the weight of the water.

  1. True

  2. False


Correct Option: A
Explanation:

Objects weigh more in air than in water. When submerged, the 3 N block appears to weigh only 1 N. The missing weight is equal to the weight of the water displaced. The 2 N weight is equal to the buoyant force.
That is, Loss in weight of body = Weight of water (liquid) displaced by the body = Buoyant force or upthrust exerted by water (any liquid) on the body.

A body of density 5.34  $ \displaystyle g/cm^{3} $ when immersed in water (density 1.0$ \displaystyle g/cm^{3} $ ) will 

  1. float

  2. sink

  3. rise

  4. none of these


Correct Option: B
Explanation:

 

Any solid floats on water if its density is less than the density of water(i.e. 1).So, it will sink.

A piece of iron [density 7.6$ \displaystyle gcm^{-3} $] sinks in mercury [density 13.6 $ \displaystyle gcm^{-3} $]. State whether true or false.

  1. True

  2. False


Correct Option: B
Explanation:

Since condition for sinking of a body of density $\sigma $ in a liquid of density S is 

                  $\sigma >S.$
& Since iron of density 7.69/cc is less lighter than density of mercury (density 13.6g/cc). Hence iron will float on mercury.

A piece of iron sinks in water but can float in mercury. True or false.

  1. True

  2. False


Correct Option: A
Explanation:

Conditions for sinking of a body of density $\sigma $ in a liquid of density S is 

           $\sigma \quad >\quad S$
hence iron sink in water & float in mercury as iron is lighter than mercury.

When an object is placed in a liquid whose density is lower than the object, the object will float. True or false.

  1. True

  2. False


Correct Option: B
Explanation:

a body of higher density would sink in a liquid of lower density 

so the given object would sink in this case
hence option (B) would be correct.