(c) Chadwick
   (d) Newton
Ans: (c)
174. For a particle revolving in a circular path the acceleration of the particle
   is: [NDA 2010]
   (a) along the tangent
   (b) along the radius
   (c) zero
   (d) along the circumference of the circle
Ans: (b)
175. The size of the atomic nucleus is in the order of : [RRB ASM/GG 2004]
   (a) 10-10 meter
   (b) 10-9 meter
   (c) 10-3 meter
   (d) 10-15 meter
Ans: (d)
176. Who was the inventor of positron? [RRB ASM 2004]
   (a) Rutherford
   (b) J.J. Thomson
   (c) Chadwick
   (d) Anderson
Ans: (d)
177. The antiparticle of the electron is called:
   (a) positron
   (b) neutrino
   (c) meson
   (d) antineutrino
Ans: (a)
178. Who was the inventor of neutrino?
   (a) Pauli
   (b) Fermi
   (c) Anderson