KVPY Government Jobs Exams

A nucleus of lead 214 Pb82 emits two electrons followed by an alpha particle. The resulting nucleus will have
option
(A) 82 protons and 128 neutrons
(B) 80 protons and 130 neutrons
(C) 82 protons and 130 neutrons
(D) 78 protons and 134 neutrons

Read Solution (Total 0)

KVPY Other Question

A 750 W motor drivers a pump which lifts 300 litres of water per minute to a height of 6 meters. The efficiency of the motor is nearly (take acceleration due to gravity to be 10 m/s2)
option
(A) 30%
(B) 40%
(C) 50%
(D) 20% The number of air molecules in a (5m × 5m × 4m) room at standard temperature and pressure is of the order of