There are $0.8 \times 10^{23}$ free electrons $/ cm^3$ in copper. If $0.2\, A $ current is flowing is copper wire, then the drift velocity of electrons will be, if the cross sectional area of wire is $0.01 \,cm^2$
Easy
Download our app for free and get started
$I = neAV_d$
Download our app
and get started for free
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.*
A wire of resistance $20 \Omega$ is divided into $10$ equal parts. A combination of two parts are connected in parallel and so on. Now resulting pairs of parallel combination are connected in series. The equivalent resistance of final combination is_______.0$\Omega$.
$A, \,B$ and $C$ are voltmeters of resistance $R, \,1 .5R$ and $3R$ respectively as shown in the figure. When some potential difference is applied between $X$ and $Y,$ the voltmeter readings are $V_A, \,V_B$ and $V_C$ respectively. Then
Forty electric bulbs are connected in series across a $220\, V$ supply. After one bulb is fused, the remaining $39$ are connected again in series across the same supply. The illumination will be
A button battery is rated $3 \,V$ and $225 \,mAh . A$ cricket ball (mass $=0.163 \,kg$ ) having energy equal to that stored in the battety will have speed closest to ............ $\,m / s$
Two identical heater filaments are connected first in parallel and then in series. At the same applied voltage, the ratio of heat produced in same time for parallel to series will be:
Two resistors $400\, \Omega$ and $800\, \Omega$ are connected in series across a $6 V$ battery. The potential difference measured by a voltmeter of $10\, k \Omega$ across $400\, \Omega$ resistor is close to$....V$
Three identical bulbs are connected as shown in figure. When switch $S$ is closed, the power consumed in bulb $B$ is $P$. What will be the power consumed by the same bulb when switch $S$ is opened?