NEET UG PHYSICS MCQ: SEMI CONDUCTOR DEVICES

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Application +4 | -1

A metallic surface with work function of

2\;eV

, on heating to a temperature of 800

K

gives an emission current of

1\;mA

. If another metallic surface having the same surface area, same emission constant but work function

4\;eV

is heated to a temperature of

1600\;K

, then the emission current will be

View answer and explanation

Correct option: C

mA

Option D (4

mA

) is correct because the emission current is proportional to

T^2 e^{-\phi/kT}

, and with the given changes in work function and temperature, the current quadruples.

More Questions from SEMI CONDUCTOR DEVICES

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I = A{T^2}{e^{q/{V_L}}}

{V_L}

\sqrt{n}.

n

p - n\;

{10^{17}}\mathrm{c}{\mathrm{m}^{ - 3}}

P

{10^{16}}

\mathrm{c}{\mathrm{m}^{ - 3}}

N

kT =

{n_i} = 1.4 \times {10^{10}}

\mathrm{c}{\mathrm{m}^{ - 3}}