A metal ring of internal and external radii 15 mm and 20 mm respectively is placed horizontally on the surface of a liquid of surface tension 0.03 N/m To detach the ring from the liquid surface the force required isA. `28 xx 10^(-5)`NB. `66xx10^(-4)`NC. `6.6 xx10^(-4)`ND. `425 xx 10^(-4)`N

A metal ring of internal and external radii 15 mm and 20 mm respective

1.	A metal ring of internal and external radii 15 mm and 20 mm respectively is placed horizontally on the surface of a liquid of surface tension 0.03 N/m To detach the ring from the liquid surface the force required isA. `28 xx 10^(-5)`NB. `66xx10^(-4)`NC. `6.6 xx10^(-4)`ND. `425 xx 10^(-4)`N
Answer» Correct Answer - B `2pi (r+R)T = =F` ` F = 2pi (15xx 10^(-3) + 20 xx 10^(-3))xx3 xx 10^(-2)` ` 2pi (35) xx 10^(-3) xx 3xx 10^(-2)` ` = 659.7 xx10^(-5)` ` = 66 xx 10^(-4)` N

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A metal ring of internal and external radii 15 mm and 20 mm respectively is placed horizontally on the surface of a liquid of surface tension 0.03 N/m To detach the ring from the liquid surface the force required isA. `28 xx 10^(-5)`NB. `66xx10^(-4)`NC. `6.6 xx10^(-4)`ND. `425 xx 10^(-4)`N

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