NEET Physics Question - Modern Physics - Photoelectric Effects and deBroglie Equation

Assertion (A): When the speed of an electron increases its specific charge decreases.

Reason (R): Specific charge is the ratio of the mass to charge.

Both (A) & (R) are true and the (R) is the correct explanation of the (A)

Both (A) & (R) are true but the (R) is not the correct explanation of the (A)

(A) is true but (R) is false

Both (A) and (R) are false

Solution:

Assertion (A) is true: relativistic mass \(m = m_0 \sqrt{1-v^2/c^2}\) increases with speed \(v\), so specific charge \(q/m\) decreases. Reason (R) is false because specific charge is defined as the ratio of charge to mass (\(q/m\)), not mass to charge.

Rankers Physics

Specific Charge and Electron Speed

Solution:

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