A hot filament liberates an electron with zero initial velocity. The anode potential is $$1200 \mathrm{~V}$$. The speed of the electron when it strikes the anode is
A metal rod of length $$10 \mathrm{~cm}$$ and a rectangular cross-section of $$1 \mathrm{~cm} \times \frac{1}{2} \mathrm{~cm}$$ is connected to a battery across opposite faces. The resistance will be
A car has a fresh storage battery of emf $$12 \mathrm{~V}$$ and internal resistance $$2 \times 10^{-2} \Omega$$. If the starter motor draws a current of $$80 \mathrm{~A}$$. Then, the terminal voltage when the starter is On is
A potentiometer has a uniform wire of length $$5 \mathrm{~m}$$. A battery of emf $$10 \mathrm{~V}$$ and negligible internal resistance is connected between its ends. A secondary cell connected to the circuit gives balancing length at $$200 \mathrm{~cm}$$. The emf of the secondary cell is