Question 14A jeweller claims that he makes ornament of pure gold of relative density 19.3. He sells a bangle weighing 25.25 gf to a person. The clever customer weighs the bangle when immersed in water and finds that it weighs 23.075 gf in water. With the help of suitable calculations find out whether the ornament is made of pure gold or not.[Hint — Calculate R.D of material of bangle which comes out to be 11.6]

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Bright Tutorials · Accepted Answer

Given,Relative density of pure gold = 19.3Weight of the bangle in air (W1) = 25.25 gfWeight of the bangle in water (W2) = 23.075 gfRelative density of bangle=(W1W1−W2)=(25.2525.25−23.075)=(25.252.175)=11.6\text{Relative density of bangle} = \big(\dfrac{\text W_{1}}{\text W_{1} − \text W_{2}}\big) \[1 em] = \big(\dfrac{25.25}{25.25 - 23.075}\big) \[1 em] = \big(\dfrac{25.25}{2.175}\big) \[1 em] = 11.6Relative density of bangle=(W1​−W2​W1​​)=(25.25−23.07525.25​)=(2.17525.25​)=11.6It is given that relative density of gold is 19.3 where as relative density of bangle is 11.6.Hence, we can deduce that the bangle is not made of pure gold.

Upthrust in Fluids, Archimedes' Principle and Floatation — Question 14

Question 14