The normal duratioin of I.Sc. Physics practical period in Indian colleges is 100 minute. Express this perod in microcenturies. 1 microcentruy `=10^-6xx100` years. How many microcenturies did you sleep yesterday?

Consider a coin of Question 20. It is electrically neutral and contains equal amounts of positive and negative charge of magnitude 34.8 kC. Suppose that these equal charges were concentrated in two point charges separated by: (i) 1 cm (-1/2) xx displacement of the one paisa coin) (ii) 100 m (-length of a long building) (iii) 10^(6) m (radius of the earth). Find the force on each such point charge in each of the three cases. What do you conclude from these results ?

Consider a coin of Question 20 . It is electrically neutral and contains equal amounts of positive and negative charge of magnitude 34.8 kC. Suppose that these equal charges were concentrated in two point charges separated by (i) 1cm (~(1)/(2)xx diagonal of the one paisa coin ) (ii) 100 m ( ~ length of a long building) (iii) 10^(6)m (radius of the earth). find the force on each such point charge in each of the three cases. what do you conclude from these results?

Suppose India had a target of producing by 2020 AD, 200,000 MW of electric power , 10% of which was to be obtained from nuclear power plant. Suppose we are given that, on an average, the efficiency of utilisation (i.e., conversion to electric energy ) of thermal energy produced in a reactor was 25% . How much amount of fissionable uranium did our country need per year by 2020 ? Take the heat per fission of .^235U to be about 200 MeV. Avogadro's number =6.023xx10^(-23) mol^(-1) .