GATE Electronics and Communications (EC) 2014 Shift 2 Solved Paper

Assume electronic charge q = 1.6 × 10^-19 C, kT/q = 25 mV and electron mobility μ_n = 1000 cm²/V-s. If the concentration gradient of electrons injected into a P-type silicon sample is 1 × 10²¹/cm⁴, the magnitude of electron diffusion current density (in A/cm²) is _________.