A and B are two radioactive substances whose half lives are 1 and 2 – McqOptions

MCQOPTIONS

1.	A and B are two radioactive substances whose half lives are 1 and 2 years respectively. Initially 10 gm of A and 1 gm of B is taken. The time (approximate) after which they will have same quantity remaining is [UPSEAT 2003]
A.	6.62 years
B.	5 years
C.	3.2 years
D.	7 years
Answer» B. 5 years

Discussion

No Comment Found

Related MCQs

Find the equivalent thermal resistance of combination of rods as shown in figure. Every rod has same length I and cross-sectional area A. Thermal conductivities are mentioned in figure.
The ripple factor in a half wave rectifier is [RPMT 2002]
Assertion : Two persons on the surface of moon cannot talk to each other. Reason : There is no atmosphere on moon.
A potential barrier of 0.50 V exists across a P-N junction. If the depletion region is \[5.0\times {{10}^{-7}}\]m wide, the intensity of the electric field in this region is [UPSEAT 2002]
The laptop PC?s modern electronic watches and calculators use the following for display
The reason of current flow in P-N junction in forward bias is [RPMT 2000]
The period of a simple pendulum is doubled, when [CPMT 1974; MNR 1980; AFMC 1995; Pb. PET/PMT 2002]
The period of oscillation of a simple pendulum of constant length at earth surface is T. Its period inside a mine is [CPMT 1973; DPMT 2001]
Assertion : To protect any instrument from external magnetic field, it is put inside an iron body. Reason : Iron is a magnetic substance.
Two travelling waves \[{{y}_{1}}=A\sin [k(x-ct)]\] and\[{{y}_{2}}=A\sin [k(x+ct)]\]are superimposed on string. The distance between adjacent nodes is