(a) A sample of a radioactive isotope contains N nuclei at time t. At time (t + At), it contains (N-AN) nuclei of the isotope. For the period At, state, in terms of N, AN and At, (i) the mean activity of the sample, activity = (ii) the probability of decay of a nucleus. probability = [1] [1] (b) A cobalt-60 source having a half-life of 5.27 years is calibrated and found to have an activity of 3.50 x 105 Bq. The uncertainty in the calibration is ±2%. Calculate the length of time, in days, after the calibration has been made, for the stated activity of 3.50 x 105 Bq to have a maximum possible error of 10%.

R=300 and e= 12.0 V.  Find the equivalent resistance when open Find the equivalent resistance when closed.

12V ww 14 20 a ww b. 13 12 8V

"Explain the concept of CIDR (Classless Inter-Domain Routing) and its role in modern IP networking. Discuss how CIDR enables more flexible allocation of IP addresses by allowing variable-length subnet masking. Describe the structure of CIDR notation and how it represents both IP address and subnet mask information. Explore the benefits of CIDR, such as efficient address allocation, route aggregation, and improved scalability in the context of internet routing. Additionally, discuss the relationship between CIDR and IPv6 adoption."