List of top Physics Questions on Radioactive Decay asked in KCET

The natural logarithm of the activity \( R \) of a radioactive sample varies with time \( t \) as shown. At \( t = 0 \), there are \( N_0 \) undecayed nuclei. Then \( N_0 \) is equal to \([\text{Take} \ e^{7.5}] \)

Dimensional formula for activity of a radioactive substance is