Find the number of photons emitted per second from of source of light which results in a photocurrent with drift velocity of $1.5\ m/s$ in a conductor with cross-section area $0.25\ m^2$ , volume density of electrons $10^{20}\ per \ m^3$ , (Assume that $60\%$ of photons emitted result in electron emission)
  • A$6.25 \times 10^{19}$
  • B$6.25 \times 10^{20}$
  • C$6 \times 10^{19}$
  • D$6 \times 10^{20}$
Medium
art

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.*

Similar Questions

  • 1
    Three bulbs of $40\,W$, $60\,W$ and $100\,W$ are arranged in series with $220\,V$. Which bulb has minimum resistance............... $W$
    View Solution
  • 2
    Resistance of tungsten wire at $150\,^oC$ is $133\,\Omega $. Its resistance temperature coefficient is $0.0045\,^oC$. The resistance of this wire at $500\,^oC$ will be .............. $\Omega$
    View Solution
  • 3
    If two bulbs of wattage $25$ and $30$, each rated at $220\, volts$, are connected in series with a $440$ $volt$ supply, which bulb will fuse
    View Solution
  • 4
    A potentiometer has uniform potential gradient. The specific resistance of the material of the potentiometer wire is $10^{-7} \, ohm-meter$ and the current passing through it is $0.1\, ampere$; cross-section of the wire is $10^{-6}\, m^2$. The potential gradient along the potentiometer wire is
    View Solution
  • 5
    A meta sample carrying a current along $x-$ axis with density $J$ is subjected to a magnetic field $B$ (along $z-$ axis). The electric field $E$ developed along $y-$ axis is directly proportional to $J$ as well as $B$. The constant of proportionality has $SI\  unit$
    View Solution
  • 6
    Equivalent resistance between $A$ and $B$ will be ............ $ohm$
    View Solution
  • 7
    You are given several identical resistances each of value $R = 10\,\Omega $ and each capable of carrying maximum current of $1\, ampere$. It is required to make a suitable combination of these resistances to produce a resistance of $5\,\Omega $ which can carry a current of $4\, amperes$. The minimum number of resistances of the type $R$ that will be required for this job
    View Solution
  • 8
    In the below circuit the current in each resistance is
    View Solution
  • 9
    A voltmeter of resistance $1000\,\Omega$ is connected across a resistance of $500\, \Omega$ in the given circuit. What will be the reading of voltmeter .............. $V$
    View Solution
  • 10
    In the circuit shown, the current through the $4\,\Omega $ resistor is $1\, amp$ when the points $P$ and $M$ are connected to a d.c. voltage source. The potential difference between the points $M$ and $N$ is ............... $volt$
    View Solution