Length of a hollow tube is $5\,m$, it’s outer diameter is $10\, cm$ and thickness of it’s wall is $5\, mm$. If resistivity of the material of the tube is $1.7 \times 10^{-8} \,\Omega m$ then resistance of tube will be
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Some electric bulbs are connected in series across a $220\, V$ supply in a room. If one bulb is fused then remaining bulbs are connected again in series across the same supply. The illumination in the room will
A piece of wire is cut into four equal parts and the pieces are bundled together side by side to form a thicker wire. Compared with that of the original wire, the resistance of the bundle is ..........
The resistance per centimeter of a meter bridge wire is $\mathrm{r}$, with $\mathrm{X}\ \Omega$ resistance in left gap. Balancing length from left end is at $40 \mathrm{~cm}$ with $25\ \Omega$ resistance in right gap. Now the wire is replaced by another wire of $2 \mathrm{r}$ resistance per centimeter. The new balancing length for same settings will be at
A uniform wire of resistance $20\,ohm$ having resistance $1\Omega /m$ is bent in the adjoining form of a circle as shown in the figure. If the equivalent resistance between $M$ and $N$ is $1.8 \,\Omega $, then the length of the shorter section is ................ $m$
Under what condition current passing through the resistance $R$ can be increased by short circuiting the battery of emf $E_2$. The internal resistances of the two batteries are $r_1$ and $r_2$ respectively.
An insulating pipe of cross-section area $'A'$ contains an electrolyte which has two types of ions $\rightarrow$ their charges being $-e$ and $+2e$. $A$ potential difference applied between the ends of the pipe result in the drifting of the two types of ions, having drift speed $= v$ ($-ve$ ion) and $v/4$ ($+ve$ ion). Both ions have the same number per unit volume $= n$. The current flowing through the pipe is