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TS EAMCET · Physics · Semiconductors

If the ratio of electron and hole currents in a semiconductor is \(\frac{7}{4}\) and the ratio of drift velocities of electrons and holes is \(\frac{5}{4}\), then ratio of concentrations of electrons and holes will be

  1. A \(5: 7\)
  2. B \(7: 5\)
  3. C \(5: 9\)
  4. D \(9: 5\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(7: 5\)

Step-by-step Solution

Detailed explanation

Ratio of electron \& Hole current, \[ \frac{\mathrm{I}_{\mathrm{e}}}{\mathrm{I}_{\mathrm{n}}}=\frac{7}{4} \] Ratio of velocities, \(\frac{v_e}{v_n}=\frac{5}{4}\) Current is given by: \(\mathrm{I}=\mathrm{ne}_{\mathrm{d}}\). \[ \mathrm{n}=\frac{\mathrm{I}}{\mathrm{eAV}} \] Ratio…