TS EAMCET · Physics · Nuclear Physics
If \(87.5 \%\) of atoms of a radioactive element decay in 6 days, then the fraction of atoms of the element that decay in 8 days is
- A \(\frac{1}{8}\)
- B \(\frac{7}{8}\)
- C \(\frac{1}{16}\)
- D \(\frac{15}{16}\)
Answer & Solution
Correct Answer
(D) \(\frac{15}{16}\)
Step-by-step Solution
Detailed explanation
\(N/N_0 = 1 - 0.875 = 0.125 = 1/8\) \( (1/2)^{t/T} = 1/8 \Rightarrow t/T = 3 \) \(T = 6 \text{ days} / 3 = 2 \text{ days}\) \(t' = 8 \text{ days}, N'/N_0 = (1/2)^{8/2} = (1/2)^4 = 1/16\) \(\text{Fraction decayed} = 1 - 1/16 = 15/16\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A charge \(Q\) is divided into two charges \(q\) and \(Q-q\). The value of \(q\) such that the force between them is maximum, isTS EAMCET 2014 Easy
- 'A horizontal uniform glass tube of \(100 \mathrm{~cm}\), length sealed at both ends contains \(10 \mathrm{~cm}\) mercury column in the middle. The temperature and pressure of air on either side of mercury column are respectively \(31^{\circ} \mathrm{C}\) and \(76 \mathrm{~cm}\) of mercury. If the air column at one end is kept at \(0^{\circ} \mathrm{C}\) and the other end at \(273^{\circ} \mathrm{C}\), then the pressure of air which is at \(0^{\circ} \mathrm{C}\) is : (in \(\mathrm{cm}\) of \(\mathrm{Hg}\) )TS EAMCET 2003 Medium
- One litre of oxygen at a pressure of \(1 \mathrm{~atm}\) and two litres of nitrogen at a pressure of \(0.5 \mathrm{~atm}\), are introduced into a vessel of volume \(1 \mathrm{~L}\). If there is no change in temperature, the final pressure of the mixture of gas (in atm) isTS EAMCET 2008 Hard
- The operation of a nuclear reactor is said to be critical when the value of neutron multiplication factor \(K\) isTS EAMCET 2024 Easy
- A ball of mass \(0.2 \mathrm{~kg}\) is thrown from a height of \(1 \mathrm{~m}\) and with an initial velocity of \(\sqrt{10} \mathrm{~m} / \mathrm{s}\) at an angle of \(45^{\circ}\) with the horizontal. Assuming, acceleration due to gravity \(g=10 \mathrm{~m} /\) \(\mathrm{s}^2\), then modulus of momentum increment during the total time of motion in \(\mathrm{kg} \mathrm{m} / \mathrm{s}\) isTS EAMCET 2018 Easy
- A meteor of mass ' \(m\) ' having a speed ' \(v\) ' at infinity reaches the surface of the earth with a speed of ( \(\mathrm{v}_{\mathrm{e}}\) is escape speed from the earth's surface)TS EAMCET 2025 Medium
More PYQs from TS EAMCET
- The thermo emf of a thermocouple is given by, \(E=a T+b T^2\), where \(\frac{a}{b}=-200^{\circ} \mathrm{C}\). If the cold function is kept at \(30^{\circ} \mathrm{C}\), then the inversion temperature is ( \(\varepsilon\) in volt, \(T\) in centigrade)TS EAMCET 2010 Medium
- Two small spheres each having equal positive charge \(Q\) (Coulomb) on each are suspended by two insulating strings of equal length \(L\) (metre) from a rigid hook (shown in figure). The whole set up is taken into satellite where there is no gravity. The two balls are now held by electrostatic forces in horizontal position, the tension in each string is then
TS EAMCET 2012 Medium - Currents flowing in each of the following circuits \(A\) and \(B\) respectively are
TS EAMCET 2009 Easy - Three particles, each of mass , situated at the vertices of an equilateral triangle of side length . The only forces acting on the particles are their mutual gravitational forces. It is desired that each particle moves in a circle while maintaining the original separation . The initial speed that should be given to each particle isTS EAMCET 2022 Easy
- Particles and their anti-particles haveTS EAMCET 2005 Medium
- Velocities (V) and accelerations (a) in two systems of units 1 and 2 are related as \(V_2=\frac{n}{m^2} V_1\) and \(a_2=\frac{a_1}{m n}\) respectively. Here \(\mathrm{m}\) and \(\mathrm{n}\) are constants. Dimensionally relations between distances \(\left(\mathrm{S}_1\right.\) and \(\left.\mathrm{S}_2\right)\) and times \(\left(\mathrm{t}_1\right.\) and \(t_2\) ) in the two systems are respectively.TS EAMCET 2023 Easy