Polarization impossible in: MCQ with Answer and Explanation

Explanation:
Hydrogen fusion to helium releases energy.

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.

Explanation:
Sound travels to cliff and back. Total distance = speed × time = 340 × 2 = 680 m. So distance to cliff = 680/2 = 340 m. Use formula d = (v × t)/2. Time for round trip. Minimum distance for echo 17 m (approx) for 0.1 s persistence.