Question

The U-tabe with limbs of diameters 5 mm and 2 mm contains water of surface tension `7 xx 10^(-2)Nm^(-1)`. The angle of contact is zero and density `10^(3)kg m^(-3)`. If g is `10ms^(-2)` then, the difference in levela in the twa limbs is
A. `8.4` cm
B. `8.4` mm
C. `8.4` m
D. `0.84` mm

Answer 1

Correct Answer - B
`h_(2)-h_(1)=(2Tcos theta )/2 (1/(r^(2))-1/(r_(1)))`
` = (2 xx 7xx 10^(-2) xx1)/(10^(3) xx 10xx 10^(-3)) (1/1-1/25)= 8.4mm`