A semiconductor $$\mathrm{X}$$ is made by doping silicon with phosphorous. A second semiconductor $$\mathrm{Y}$$ is made by doping silicon with aluminium. The two are joined by a suitable technique to form a $$\mathrm{p}$$-$$\mathrm{n}$$ junction and is connected to a battery such that $$\mathrm{Y}$$ is joined to negative of the battery and $$\mathrm{X}$$ to the positive of the battery. Which of the following statements is correct?
If $$\alpha, \beta$$ and $$\gamma$$ are the angles between the vectors $$\overrightarrow{\mathrm{P}}, \overrightarrow{\mathrm{Q}}$$, and $$\overrightarrow{\mathrm{R}}$$ and $$\alpha=90^{\circ}$$ as shown in figure. the product of $$(\vec{Q} \times \vec{R}) \cdot \vec{Q}$$ is equal to
In Young's double slit experiment, the ratio of intensities of light from one slit to the other is $$9: 1$$. If Im is the maximum intensity, what is the resultant intensity when they interfere at phase difference $$\phi$$ ?
In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is $$\lambda$$ is $$\mathrm{K}$$ units ($$\lambda$$ is the wavelength of light used). The percentage change in intensity at a point where the path difference is $$\frac{\lambda}{6}$$ and the above point is