The phenomenon of radioactivity was discovered by

A. Rutherford

B. Bohr

C. Henri Bacquerel

D. Marie Curie

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  1. When we tighten the string of a sitar or tanpura its pitch
  2. X-rays are used
  3. Expansion of a rod when heated
  4. Which of the following wires of same dimensions offers least resistance to the ,flow of current?
  5. Atoms which have the same atomic number but different mass numbers are called
  6. The cell that can be recharged, after it has run down, by passing a direct current through it from a…
  7. The phenomenon of radioactivity was discovered by
  8. Antiparticle of electron is
  9. The spectrum of white light can be studied by
  10. The number of electrons in the outer orbits of a nucleus gives
  11. Photocells are used
  12. The colour of the light which travels through glass with minimum speed is
  13. A light year means
  14. An astronomical unit of distance is
  15. The velocity of sound in air
  16. The star nearest to the sun is
  17. During thunder storm you are travelling in a car. To protect yourself from the lightning you will have…
  18. Out of the following which element has the longest half-life period?
  19. The difference between planets and stars is
  20. A rheostat is used
  21. The temperature, surface features, length of days and nights of a planet depend on
  22. The escape velocity of a satellite projected from the surface of the earth is independent of
  23. Sound waves In 'air travel faster if
  24. X-rays were discovered by
  25. Dioptre is the unit of power of
  26. In which of the following will a piece of iron weigh most?
  27. Sound waves
  28. It is difficult to bon potatoes at the top or a mountain because
  29. At what temperature do the Fahrenheit and Celsius scales give the same reading?
  30. The SI unit of electric current is