TS EAMCET · Physics · Nuclear Physics
A certain radioactive element disintegrates with a decay constant of \(7.9 \times 10^{-10} / \mathrm{s}\). At a given instant of time, if the activity of the sample is equal to \(55.3 \times 10^{11}\) disintegration/second, then number of nuclei at that instant of time is
- A \(7.0 \times 10^{21}\)
- B \(4.27 \times 10^{13}\)
- C \(4.27 \times 10^3\)
- D \(6 \times 10^{23}\)
Answer & Solution
Correct Answer
(A) \(7.0 \times 10^{21}\)
Step-by-step Solution
Detailed explanation
Decay constant, \(\lambda=7.9 \times 10^{-10} /\) second Activity, \(\quad A=55.3 \times 10^{11} \frac{\text { disintegration }}{\text { second }}\) Let the number of nuclei at that instant be \(N\). We know activity, \(A=\lambda N\)…
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 circular loop and a square loop are formed from two wires of same length and cross section. Same current is passed through them. Then, the ratio of their dipole moments isTS EAMCET 2015 Easy
- Statement (I) : A uniform electric field and a uniform magnetic field are pointed in the same direction. If an electron is projected in the same direction the electron velocity will decrease in magnitude. Statement (II) : Two infinite long parallel wires are carrying current in the same direction. The magnetic field at a point midway between the wires is zero. Statement (III) : No net force acts on a rectangular coil carrying a steady current when suspended in a uniform magnetic field. Which of the following is correct?TS EAMCET 2022 Medium
- 1. The focal lengths of the objective and the eyepiece of a compound microscope are \(2 \mathrm{~cm}\) and \(3 \mathrm{~cm}\) respectively and the distance between them is \(15 \mathrm{~cm}\). The final image formed by the eyepiece is at infinity. The distances of the object and the image produced by the object from the objective lens are respectivelyTS EAMCET 2023 Easy
- An object moves in a straight line with deceleration whose magnitude varies with velocity as \(3 v^{2 / 3}\). If at an initial point, the velocity is \(8 \mathrm{~m} / \mathrm{s}\), then the distance travelled by the object before it stops isTS EAMCET 2018 Medium
- A body of mass \(M \mathrm{~kg}\) is on the top point of a smooth hemisphere of radius \(5 \mathrm{~m}\). It is released to slide down the surface of the hemisphere. It leaves the surface when velocity is \(5 \mathrm{~m} / \mathrm{s}\). At this instant the angle made by the radius vector of the body with the vertical is (Acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\) )TS EAMCET 2002 Medium
- The magnetic susceptibility of the material of a rod is 499. Permeability of vaccum is \(4 \pi \times 10^{-7} \mathrm{H} / \mathrm{m}\). Absolute permeability of the material of the rod in \(\mathrm{H} / \mathrm{m}\) is:TS EAMCET 2003 Medium
More PYQs from TS EAMCET
- A straight rod of length \(L\) is made of a material having mass per unit length \(m(x)=\lambda|x|\), where \(x\) is measured from the centre of rod. The moment of inertia about an axis perpendicular to the rod and passing through one end of the rod will be \(L=1 \mathrm{~m}\) and \(\lambda=16 \mathrm{~kg} / \mathrm{m}^2\).TS EAMCET 2020 Medium
- A bullet of mass fired with a speed from passes through a block of wood whose centre is kept at a distance of from the origin as shown in figure. The retarding force on the bullet within the wooden block is . The minimum length of the block (upto one decimal digit) required to completely stop the bullet is (Assume )TS EAMCET 2019 Medium
- Two particles having position vectors \(\mathbf{r}_1=(3 \hat{\mathbf{i}}+5 \hat{\mathbf{j}})\) metres and \(\mathbf{r}_2=(-5 \hat{\mathbf{i}}-3 \hat{\mathbf{j}})\) metres are moving with velocities \(\mathbf{v}_1=(4 \hat{\mathbf{i}}+3 \hat{\mathbf{j}}) \mathrm{m} / \mathrm{s}\) and \(\mathbf{v}_2=(a \hat{\mathbf{i}}+7 \hat{\mathbf{j}}) \mathrm{m} / \mathrm{s}\). If they collide after \(2 \mathrm{~s}\), then the value of \(a\) is :TS EAMCET 2003 Medium
- A photon released by the transition of an electron from the second excited state to the ground state of Hydrogen atom is incident on the surface of a metal of work function \(3.1 \mathrm{eV}\). The de Broglie wavelength of the most energetic electron emitted from that metal surface is nearlyTS EAMCET 2023 Easy
- Assertion : Heat and work are modes of energy transfer to a system resulting in change in its internal energy. Reason : Heat and work in thermodynamics are state variables. The correct option among the following isTS EAMCET 2022 Medium
- String of unstretched length is stretched by applying a force at the mid-point such that the segments and make an anglewith as shown in the figure. The string may be considered as an elastic element with a force to elongation ratio . The force is given by
TS EAMCET 2018 Medium