Practicing Success
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The ratio of work function and temperature of two emitters are 1 : 2, then the ratio of current densities obtained by them will be |
4 : 1 2 : 1 1 : 2 1 : 4 |
1 : 4 |
$\frac{J_1}{J_2}=\frac{AT_1^2e^{-W_1/kT_1}}{AT_2^2e^{-W_2/kT_2}}=(\frac{T_1}{T_2})^2e^{-\frac{W_1}{kT_1}+\frac{W_2}{kT_2}}=(\frac{1}{2})^2e^0=\frac{1}{4}$ |
