The mass number of an element is sum of MCQ with Answer and Explanation

Explanation:
3.600 has 4 significant figures (3,6,0,0). Trailing zeros after decimal are significant due to precision.

Explanation:
g = 4π²l/T² ⇒ %Δg = %Δl + 2×%ΔT. Assuming l precise: %Δg ≈ 2×(0.1/2.0×100%) = 2×5% = 10%. Memory tip: 'g ∝ 1/T² ⇒ %Δg = 2×%ΔT'. Error analysis frequently tested in competitive experimental physics sections.

Explanation:
Seismograph detects and records ground motions caused by earthquakes, volcanic activity, or explosions. It measures seismic waves (P-waves, S-waves). Barometer detects pressure changes; hydrophone detects underwater sound; magnetometer detects magnetic fields. Memory tip: 'Seismo = earthquake (like seismology)'. This instrument-application question tests knowledge of geophysical tools, frequently examined in competitive exams. Always associate instrument names with their field of use: seismograph (geology), barometer (meteorology), etc.