1 |
The half life of radioactive elements depends upon |
Temperature
Nature of element
Amount of the radioactive substance
Pressure
|
2 |
Half life of Uranium -239 is |
26.5 minutes
24.5 minutes
25.5 minutes
23.5 minutes
|
3 |
Materials can be identified by measuring their |
Mass
Half life
Both a and b
None of a,b,c
|
4 |
Half life of radon gas is |
3.8 minutes
3.8 days
3.8 months
3.8 years
|
5 |
The force which is responsible for the breaking up of the radioactive element is. |
Weak nuclear force
Strong nuclear force
Electromagnetic force
Gravitational force
|
6 |
X -rays are similar in nature to. |
Gama rays
Beta rays
Alpha rays
Cathode rays
|
7 |
Marie Curie and Pierre Curie discovered. |
Uranium
Uranium and Radium
Polonium and radium
Radium
|
8 |
When gama rays are emitted, the nuclear mass. |
Decreases by 4 units
Does not change
Increases by 2 units
Increase by 1 unit
|
9 |
The activity of radioactive sample |
Is constant
Increases with time
Decreases linearly with time
Decreases exponentially with time
|
10 |
There is no charge in A and Z of any radioactive element by the emission of. |
Alpha particle
Beta particle
Gama particle
X- rays
|
11 |
Which one of the following is not affected by electric or magnetic field. |
Beta rays
Gama ryas
Alpha rays
Electron
|
12 |
The reciprocal of decay construct lamda of a radioactive element is. |
Half life
Mean life
Curie
total life
|
13 |
When a nucleus emits an alpha particle, its atomic mass decreases by |
1
2
3
4
|
14 |
The charge of an alpha particle is equal to |
-e
+e
-2e
2e
|
15 |
Binding energy per nucleon is maximum for |
Platinum
Iron
Uranium
Lead
|
16 |
Energy released by conversion of 1 amu is |
200 MeV
931 MeV
233 MeV
243 MeV
|
17 |
Which is true for both alpha particle and gama rays. |
They cause ionization in air
They can be deflected by electric field
They can be deflected by magnetic field
The y can penetrate a few millimeters of aluminium
|