JEE Main 2025 (Online) 7th April Evening Shift | Properties of Matter Question 4 | Physics

A capillary tube of radius 0.1 mm is partly dipped in water (surface tension 70 dyn/cm and glass water contact angle ≈ 0°) with 30° inclined with the vertical. The length of water risen in the capillary is _______ cm. (Take $g = 9.8 \text{ m/s}^2$)

$\frac{82}{5}$

$\frac{68}{5}$

$\frac{57}{2}$

$\frac{71}{5}$

JEE Main 2025 (Online) 2nd April Evening Shift

MCQ (Single Correct Answer)

-1

Two water drops each of radius ' $r$ ' coalesce to form a bigger drop. If ' $T$ ' is the surface tension, the surface energy released in this process is :

$4 \pi \mathrm{r}^2 \mathrm{~T}\left[2-2^{1 / 3}\right]$

$4 \pi \mathrm{r}^2 \mathrm{~T}[1+\sqrt{2}]$

$4 \pi \mathrm{r}^2 \mathrm{~T}\left[2-2^{2 / 3}\right]$

$4 \pi \mathrm{r}^2 \mathrm{~T}[\sqrt{2}-1]$

JEE Main 2025 (Online) 29th January Morning Shift

MCQ (Single Correct Answer)

-1

The fractional compression $\left( \frac{\Delta V}{V} \right)$ of water at the depth of 2.5 km below the sea level is __________ %. Given, the Bulk modulus of water = $2 \times 10^9$ N m$^{-2}$, density of water = $10^3$ kg m$^{-3}$, acceleration due to gravity $g = 10$ m s$^{-2}$.

1.0

1.25

1.75

1.5

JEE Main 2025 (Online) 28th January Evening Shift

MCQ (Single Correct Answer)

-1

A 400 g solid cube having an edge of length 10 cm floats in water. How much volume of the cube is outside the water?

(Given: density of water = 1000 kg m^-3)

400 cm³

600 cm³

1400 cm³