1
WB JEE 2024
MCQ (Single Correct Answer)
+1
-0.25
Change Language

Three point charges $$\mathrm{q},-2 \mathrm{q}$$ and $$\mathrm{q}$$ are placed along $$x$$ axis at $$x=-{a}, 0$$ and $a$ respectively. As $$\mathrm{a} \rightarrow 0$$ and $$\mathrm{q} \rightarrow \infty$$ while $$\mathrm{q} \mathrm{a}^2=\mathrm{Q}$$ remains finite, the electric field at a point P, at a distance $$x(x \gg a)$$ from $$x=0$$ is $$\overrightarrow{\mathrm{E}}=\frac{\alpha \mathrm{Q}}{4 \pi \epsilon_0 x^\beta} \hat{i}$$. Then

A
$$\alpha=\beta$$
B
$$\alpha=2 \beta$$
C
$$\alpha=\frac{2}{3} \beta$$
D
$$2 \alpha=3 \beta$$
2
WB JEE 2024
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A body floats with $$\frac{1}{n}$$ of its volume keeping outside of water. If the body has been taken to height $$\mathrm{h}$$ inside water and released, it will come to the surface after time t. Then

A
$$t \propto \sqrt{n}$$
B
$$\mathrm{t} \propto \mathrm{n}$$
C
$$t\propto \sqrt{n+1}$$
D
$$t \propto \sqrt{n-1}$$
3
WB JEE 2024
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A small sphere of mass m and radius r slides down the smooth surface of a large hemispherical bowl of radius R. If the sphere starts sliding from rest, the total kinetic energy of the sphere at the lowest point $$\mathrm{A}$$ of the bowl will be [given, moment of inertia of sphere $$=\frac{2}{5} \mathrm{mr}^2$$]

WB JEE 2024 Physics - Rotational Motion Question 3 English

A
$$\mathrm{mg}(\mathrm{R}-\mathrm{r})$$
B
$$\frac{7}{10} \mathrm{mg}(\mathrm{R}-\mathrm{r})$$
C
$$\frac{2}{7}$$ mg $$(\mathrm{R}-\mathrm{r})$$
D
$$\frac{10}{7} \mathrm{mg}(\mathrm{R}-\mathrm{r})$$
4
WB JEE 2024
MCQ (Single Correct Answer)
+2
-0.5
Change Language

When a convex lens is placed above an empty tank, the image of a mark at the bottom of the tank, which is 45 cm from the lens is formed 36 cm above the lens. When a liquid is poured in the tank to a depth of 40 cm, the distance of the image of the mark above the lens is 48 cm. The refractive index of the liquid is

A
1.353
B
1.544
C
1.472
D
1.366
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