Physics MCQs: Electromagnetism and Circuits

• These notes cover multiple-choice questions in physics.
• The questions range from electromagnetism and electrical circuits to modern physics concepts like photons and wave-particle duality.

Electromagnetism and Electrical Circuits

• A toy that generates electrical energy when moved is an example of an electrical generator.
• Faraday discovered electromagnetic induction.
• In generators, the induced current changes direction every half rotation of the loop.
• The actual (effective) current value equals the RMS value, which is peak current divided by the square root of 2.
• The transformer is used for transmitting power.
• A 50 Hz current means the current changes direction 50 times per second.
• If a transformer has more turns in the secondary coil than the primary coil, it's a step-up transformer.
• Producing changing magnetic fields that induce a changing electric field relates to electromagnetism.
• Waves that result from coupled electric and magnetic field oscillations traveling through space are electromagnetic waves.
• An antenna is designed to transmit or receive electromagnetic waves.
• The range of all forms of electromagnetic radiation in order of frequency and wavelength is the electromagnetic spectrum.
• Energy that propagates or is emitted in the form of electromagnetic waves is electromagnetic radiation.
• The property of a crystal that causes it to bend or deform and generate electrical oscillations when a potential difference is applied is piezoelectricity.
• A device consisting of an antenna, coil, capacitor, demodulator, and amplifier to extract the signal information is a receiver.
• A circuit with a coil and capacitor connected to an antenna oscillates.
• Separating uranium isotopes is an application of mass spectrometry.

Modern Physics

• Einstein discovered the photon.
• Light emitted from a hot object across a range of frequencies is a continuous emission spectrum.
• The minimum frequency of incident light required to release electrons from a material is the threshold frequency.
• The shift in energy of scattered photons relates to Compton scattering.
• It’s impossible to measure a particle's momentum and position precisely at the same time, according to the Heisenberg uncertainty principle.
• De Broglie wavelength is the wavelength associated with a moving particle.
• Atoms can only change their energy in discrete amounts, not continuously.
• The release of electrons when electromagnetic radiation hits a material is the photoelectric effect.
• Quantized and discrete packets of energy form light and other forms of electromagnetic radiation e.g. photons.
• Photon energy is inversely proportional to its wavelength.

Atomic Structure

• Different forms of the same atom with the same properties, but different masses, are isotopes.