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

A beam of light of wavelength $$\lambda$$ falls on a metal having work function $$\phi$$ placed in a magnetic field B. The most energetic electrons, perpendicular to the field are bent in circular arcs of radius R. If the experiment is performed for different values of $$\lambda$$, then $$\mathrm{B}^2$$ vs. $$\frac{1}{\lambda}$$ graph will look like (keeping all other quantities constant)

A
WB JEE 2024 Physics - Dual Nature of Radiation Question 1 English Option 1
B
WB JEE 2024 Physics - Dual Nature of Radiation Question 1 English Option 2
C
WB JEE 2024 Physics - Dual Nature of Radiation Question 1 English Option 3
D
WB JEE 2024 Physics - Dual Nature of Radiation Question 1 English Option 4
2
WB JEE 2024
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A charged particle moving with a velocity $$\vec{v}=v_1 \hat{i}+v_2 \hat{j}$$ in a magnetic field $$\vec{B}$$ experiences a force $$\vec{F}=F_1 \hat{i}+F_2 \hat{j}$$. Here $$v_1, v_2, F_1, F_2$$ all are constants. Then $$\overrightarrow{\mathrm{B}}$$ can be

A
$$\vec{B}=B_1 \hat{i}+B_2 \hat{j}$$ with $$\frac{v_1}{v_2}=\frac{B_1}{B_2}$$
B
$$\vec{B}=B_1 \hat{i}+B_2 \hat{j}+B_3 \hat{k}$$ with $$\frac{v_1}{v_2}=\frac{B_1}{B_2}$$
C
$$\overrightarrow{\mathrm{B}}=\mathrm{B}_3 \hat{\mathrm{j}}$$ with $$\mathrm{B}_1=\mathrm{B}_2=0$$
D
$$\vec{B}=B_1 \hat{j}+B_2 \hat{k}$$ with $$\frac{B_1}{B_2}=\frac{v_1}{v_2}$$
3
WB JEE 2024
MCQ (Single Correct Answer)
+1
-0.25
Change Language

Two straight conducting plates form an angle $$\theta$$ where their ends are joined. A conducting bar in contact with the plates and forming an isosceles triangle with them starts at the vertex at time $$t=0$$ and moves with constant velocity $$\vec{v}$$ to the right as shown in figure. A magnetic field $$\vec{B}$$ points out of the page. The magnitude of emf induced at $$t=1$$ second will be

WB JEE 2024 Physics - Electromagnetic Induction Question 1 English

A
$$\mathrm{Bv} \tan \frac{\theta}{2}$$
B
$$2 \mathrm{Bv}^2 \tan \frac{\theta}{2}$$
C
$$2 \mathrm{Bv}^2 \cot \frac{\theta}{2}$$
D
$$2 \mathrm{Bv}^2 \sin \frac{\theta}{2}$$
4
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
$$2 \alpha=3 \beta$$
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