Q8. In equation P = Ec⁻¹, where P is momentum, E is energy and c is the speed of light. In which of

Q: What is the correct answer for CUET UG Physics Q8?

The correct answer is b. The given equation P = Ec⁻¹ can be rewritten as E = pc. This relation comes from the full relativistic energy-momentum equation, E² = (pc)² + (m₀c²)², where m₀ is the rest mass of the particle. For a particle with zero rest mass (m₀ = 0), this equation simplifies to E² = (pc)², or E = pc. Photons are massless particles, so for them, E = pc is valid. Electrons, however, have a non-zero rest mass (m

Q: Q8. In equation P = Ec⁻¹, where P is momentum, E is energy and c is the speed of light. In which of the following options, this equation is valid: (a) for an electron only (b) for a photon but not…

The correct answer is b. The given equation P = Ec⁻¹ can be rewritten as E = pc. This relation comes from the full relativistic energy-momentum equation, E² = (pc)² + (m₀c²)², where m₀ is the rest mass of the particle. For a particle with zero rest mass (m₀ = 0), this equation simplifies to E² = (pc)², or E = pc. Photons are massless particles, so for them, E = pc is valid. Electrons, however, have a non-zero rest mass (m

Q: What are the options for this CUET UG Physics question?

A. for an electron only · B. for a photon but not for an electron · C. for an electron as well as for a photon · D. neither for an electron nor for a photon

Question

Q8. In equation P = Ec⁻¹, where P is momentum, E is energy and c is the speed of light. In which of the following options, this equation is valid:
(a) for an electron only
(b) for a photon but not for an electron
(c) for an electron as well as for a photon
(d) neither for an electron nor for a photon

FirstInTest · Accepted Answer

The given equation P = Ec⁻¹ can be rewritten as E = pc. This relation comes from the full relativistic energy-momentum equation, E² = (pc)² + (m₀c²)², where m₀ is the rest mass of the particle. For a particle with zero rest mass (m₀ = 0), this equation simplifies to E² = (pc)², or E = pc. Photons are massless particles, so for them, E = pc is valid. Electrons, however, have a non-zero rest mass (m₀ ≈ 9.11 × 10⁻³¹ kg). Therefore, the full relativistic equation must be used for electrons, and E = pc is generally not valid for them unless they are extremely relativistic (where m₀c² << pc), which is not universally true. Hence, the equation is valid for a photon but not for an electron.

Answer

for an electron only

Answer

for a photon but not for an electron

Answer

for an electron as well as for a photon

Answer

neither for an electron nor for a photon

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