A h/mc
B 2h/mc
C h/(2mc)
D Zero
Explanation: Δλ = (h/mc)(1-cos90°) = (h/mc)(1-0) = h/mc = 2.43 × 10⁻¹² m (Compton wavelength).
A Is fixed
B Is continuous up to a maximum value
C Depends on temperature
D Is always zero
Explanation: Beta particles have a continuous energy spectrum from 0 to a maximum value, because energy is shared with the antineutrino.
Explanation: v = cα where α = e²/(4πε₀ℏc) ≈ 1/137 is the fine structure constant. So v ≈ c/137.
A -3.4 eV
B -6.8 eV
C -1.51 eV
D -27.2 eV
Explanation: E₂ = E₁/2² = -13.6/4 = -3.4 eV. First excited state is n=2.
A Less than primary
B More than primary
C Same as primary
D Zero
Explanation: In a step-down transformer, voltage decreases but current increases (conservation of power: VpIp = VsIs).