There is a current of $1.344\, amp$ in a copper wire whose area of cross-section normal to the length of the wire is $1\,m{m^2}$. If the number of free electrons per $c{m^3}$ is $8.4 \times {10^{22}}$, then the drift velocity would be
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In a meter bridge experiment null point is obtained at $20\, cm$ from one end of the wire when resistance $X$ is balanced against another resistance $Y$. If $X < Y$, then where will be the new position of the null point from the same end, if one decides to balance a resistance of $4X$ against $Y$ ........... $cm$
When the resistance of $9 \,\Omega$ is connected at the ends of a battery, its potential difference decreases from $40\, volt$ to $30\, volt$. The internal resistance of the battery is ............... $\Omega$
By error, a student places moving-coil voltmeter $V$ (nearly ideal) in series with the resistance in a circuit in order to read the current, as shown. The voltmeter reading will be ............ $V$
Wheatstone bridge principle is used to measure the specific resistance $\left(S_1\right)$ of given wire, having length $L$, radius $r$. If $X$ is the resistance of wire, then specific resistance is: $S_1=X\left(\frac{\pi r^2}{L}\right)$. If the length of the wire gets doubled then the value of specific resistance will be :
In a meter bridge, the balancing length from the left end (standard resistance of $1 \,ohm$ is in the right gap) is found to be $20\, cm$. The value of the unknown resistance is ............... $\Omega$
The resistance of a $5\, cm$ long wire is $10\, \Omega$. It is uniformly stretched so that its length becomes $20\, cm$. The resistance of the wire is ............. $\Omega$
A $16\, \Omega$ wire is bend to form a square loop. A $9 \,{V}$ supply having internal resistance of $1 \,\Omega$ is connected across one of its sides. The potential drop across the diagonals of the square loop is $.......\,\times 10^{-1} \,{V}$
For the arrangement of the potentiometer shown in the figure, the balance point is obtained at $a$ distance $75\,cm $ from $A$ when the key $k$ is open. The second balance point is obtained at $60\, cm$ from $A$ when the key $k$ is closed. Find the internal resistance (in $ \Omega$) of the battery $E_1$.