After two hours, one- sixteenth of the starting amount of a certain ra – McqOptions

MCQOPTIONS

1.	After two hours, one- sixteenth of the starting amount of a certain radioactive isotope remained undecayed. The half-life of the isotope is [Bihar MEE 1995; Manipal MEE 1995; EAMCET 1994 MP PMT 1997; DPMT 2002; AFMC 2000, 05]
A.	15 minutes
B.	30 minutes
C.	45 minutes
D.	1 hour
Answer» C. 45 minutes

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