[{"id":227667,"question":"The half life of radioactive elements depends upon","choices":[{"text":"Temperature","value":"A"},{"text":"Nature of element","value":"B"},{"text":"Amount of the radioactive substance","value":"C"},{"text":"Pressure","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":227666,"question":"Half life of Uranium -239 is","choices":[{"text":"26.5 minutes","value":"A"},{"text":"24.5 minutes","value":"B"},{"text":"25.5 minutes","value":"C"},{"text":"23.5 minutes","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":227665,"question":"Materials can be identified by measuring their","choices":[{"text":"Mass","value":"A"},{"text":"Half life","value":"B"},{"text":"Both a and b","value":"C"},{"text":"None of a,b,c","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227664,"question":"Half life of radon gas is","choices":[{"text":"3.8 minutes","value":"A"},{"text":"3.8 days","value":"B"},{"text":"3.8 months","value":"C"},{"text":"3.8 years","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227663,"question":"The force which is responsible for the breaking up of the radioactive element is.","choices":[{"text":"Weak nuclear force","value":"A"},{"text":"Strong nuclear force","value":"B"},{"text":"Electromagnetic force","value":"C"},{"text":"Gravitational force","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":227662,"question":"X -rays are similar in nature to.","choices":[{"text":"Gama rays","value":"A"},{"text":"Beta rays","value":"B"},{"text":"Alpha rays","value":"C"},{"text":"Cathode rays","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":227661,"question":"Marie Curie and Pierre Curie discovered.","choices":[{"text":"Uranium","value":"A"},{"text":"Uranium and Radium","value":"B"},{"text":"Polonium and radium","value":"C"},{"text":"Radium","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":227660,"question":"When gama rays are emitted, the nuclear mass.","choices":[{"text":"Decreases by 4 units","value":"A"},{"text":"Does not change","value":"B"},{"text":"Increases by 2 units","value":"C"},{"text":"Increase by 1 unit","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227659,"question":"The activity of radioactive sample","choices":[{"text":"Is constant","value":"A"},{"text":"Increases with time","value":"B"},{"text":"Decreases linearly with time","value":"C"},{"text":"Decreases exponentially with time","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":227658,"question":"There is no charge in A and Z of any radioactive element by the emission of.","choices":[{"text":"Alpha particle","value":"A"},{"text":"Beta particle","value":"B"},{"text":"Gama particle","value":"C"},{"text":"X- rays","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":227657,"question":"Which one of the following is not affected by electric or magnetic field.","choices":[{"text":"Beta rays","value":"A"},{"text":"Gama ryas","value":"B"},{"text":"Alpha rays","value":"C"},{"text":"Electron","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227656,"question":"The reciprocal of decay construct lamda of a radioactive element is.","choices":[{"text":"Half life","value":"A"},{"text":"Mean life","value":"B"},{"text":"Curie","value":"C"},{"text":"total life","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227655,"question":"When a nucleus emits an alpha particle, its atomic mass decreases by","choices":[{"text":"1","value":"A"},{"text":"2","value":"B"},{"text":"3","value":"C"},{"text":"4","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":227654,"question":"The charge of an alpha particle is equal to","choices":[{"text":"-e","value":"A"},{"text":"+e","value":"B"},{"text":"-2e","value":"C"},{"text":"2e","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":227653,"question":"Binding energy per nucleon is maximum for","choices":[{"text":"Platinum","value":"A"},{"text":"Iron","value":"B"},{"text":"Uranium","value":"C"},{"text":"Lead","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227652,"question":"Energy released by conversion of 1 amu is","choices":[{"text":"200 MeV","value":"A"},{"text":"931 MeV","value":"B"},{"text":"233 MeV","value":"C"},{"text":"243 MeV","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":227651,"question":"Which is true for both alpha particle and gama rays.","choices":[{"text":"They cause ionization in air","value":"A"},{"text":"They can be deflected by electric field","value":"B"},{"text":"They can be deflected by magnetic field","value":"C"},{"text":"The y can penetrate a few millimeters of aluminium","value":"D"},{"value":"E"}],"correctAnswer":1}]