In a series LCR circuit at resonance, the impedance is: MCQ with Answer and Explanation

Explanation:
A p-type semiconductor is created by doping a pure semiconductor (like Silicon) with a trivalent impurity (like Boron). This creates a deficiency of one electron, creating a 'hole'. These positive holes vastly outnumber the thermally generated free electrons. Thus, holes are the majority charge carriers, and electrons are the minority charge carriers.

Explanation:
Beats occur when two sound waves of slightly different frequencies interfere, causing periodic variation in amplitude (loudness). Beat frequency = |f₁ - f₂|. This is a superposition/interference phenomenon. Reflection, refraction, diffraction don't produce beats. Memory tip: 'Beats = interference of close frequencies; used in tuning instruments'. This conceptual question tests wave superposition understanding, frequently examined in competitive exams. Always distinguish beats (amplitude modulation) from resonance (amplitude increase at natural frequency).

Explanation:
F ∝ m₁m₂. Initial: 1×1 = 1. New masses 2 and 2, product 4, so force = 4F. Distance unchanged. Universal gravitation F = Gm₁m₂/r².