$$ \text { In a p-n junction, the depletion layer of thickness } 1 \mu \mathrm{m} \text { has } 0.05 \mathrm{~V} \text { potential across it. The electric field in } N C^{-1} \text { is } $$
A long horizontal wire $$\mathrm{P}$$ carries current of $$50 \mathrm{~A}$$ from left to right. It is rigidly fixed. Another fine wire $$\mathrm{Q}$$ is placed directly above and parallel to $$\mathrm{P}$$. The mass of the wire is '$$\mathrm{m}$$' $$\mathrm{kg}$$ and carries a current of '$$\mathrm{I}$$' A. The direction of current in $$\mathrm{Q}$$ and position of wire $$\mathrm{Q}$$ from $$\mathrm{P}$$ so that the wire $$\mathrm{Q}$$ remains suspended are
A record player is spinning at an angular velocity of $$45 \mathrm{~rpm}$$ just before it is turned off. It then decelerates at a constant rate of $$0.8 \mathrm{~rad} \mathrm{~s}^{-1}$$. The angular displacement is
The resistance of a wire at room temperature $$20^{\circ} \mathrm{C}$$ is found to be $$10 \Omega$$. If resistance of the wire increases by $$10 \%$$, then the temperature of the wire will be (The temperature coefficient of the material of the wire is $$0.002 /{ }^{\circ} \mathrm{C}$$)