ICSE − Q & A

Do we have to do numericals of radioactivity???

Are we supposed to memorize terms related to Lenses?

if they ask ri to find then we should do 
u=speed in vacum /speed in medium
or
aUm = speed in vacum /"

a calorimeter of mass 50g and specific heat capacity 0.42J/gC contains water at 20C a piece of metal mass 20g and specific heat capacity 0.3J/gC at 100C is added, the final temperature is 22C find the mass of water used

Hey guys Problems related to lens are not there in the scope do we have to do?
The formula 1/v - 1/u = 1/f . These sums are not there in scope

How is focal length related to r.i.?

if the value of g is not given.
which one should be used :- 9.8 OR 10????

hiiii,could someone help me with these qns??
1)in selina pg 46,qn 6
The bob of a simple pendulum is imparted a velocity of 5m/s when it is at its mean position.To what max vertical ht will it rise on reaching at its extreme position if 60% of its energy is lost in overcoming the friction of air??(Answer 0.75m)
plzz explain how to solve it.
2)pg;67 qn 2:
A fixed pulley is driven by a 100kg mass falling at a rate of 8.0m in 4s.It lifts a load of 75kgf.calc:
(a)the power input
(b)efficiency
(c)ht to which the load is raised in 4s.
I did the first part but dont know how to do the rest.Plzz help....
3)in selina,there are no experiments given for calorimetry.Then should I learn that???
plzz answer asap............

Define one dioptre

Two medical uses of SONAR???