A wire carrying a current $$I$$ along the positive $$\mathrm{x}$$-axis has length $$L$$. It is kept in a magnetic field $$\overrightarrow{\mathrm{B}}=(2 \hat{\mathrm{i}}+3 \hat{\mathrm{j}}-4 \hat{\mathrm{k}}) \mathrm{T}$$. The magnitude of the magnetic force acting on the wire is :
A bullet from a gun is fired on a rectangular wooden block with velocity $$u$$. When bullet travels $$24 \mathrm{~cm}$$ through the block along its length horizontally, velocity of bullet becomes $$\frac{u}{3}$$. Then it further penetrates into the block in the same direction before coming to rest exactly at the other end of the block. The total length of the block is :
The resistance of platinum wire at $$0^{\circ} \mathrm{C}$$ is $$2 ~\Omega$$ and $$6.8 ~\Omega$$ at $$80^{\circ} \mathrm{C}$$. The temperature coefficient of resistance of the wire is :
An electric dipole is placed as shown in the figure.
The electric potential (in 102 V) at point P due to the dipole is ($$\in_0$$ = permittivity of free space and $$\frac{1}{4 \pi \epsilon_{0}}$$ = K) :