Magnetic field around straight current-carrying wire is: MCQ with Answer and Explanation

Explanation:
Pitch is subjective perception of frequency. Higher frequency higher pitch. Amplitude determines loudness. Speed and wavelength related by v = fλ, but pitch is frequency-based. Human ear 20 Hz-20 kHz.

Explanation:
When a body is lifted against gravity, work done (mgh) is stored as gravitational potential energy. This energy can be recovered when the body falls. Kinetic energy relates to motion, thermal to heat, elastic to deformed materials. The conservation of energy principle states that work done against conservative forces becomes potential energy. Formula: PE = mgh, where h is height above reference. Memory aid: 'Potential' means stored energy due to position. This conceptual question tests energy transformation understanding, frequently appearing in work-energy theorem applications in competitive exams.

Explanation:
Sound requires material medium. Vacuum has no particles.