ICSE − Q & A

Can anyone pls show me the working of this question-A piece of ice of mass 40g is added to 200g of water at 50C.Calculate the final temperature of water when all the ice has melted.

An external resistance R is connected to a cell of internal resistance R.The current in the circuit is maximum when:
(a)R<r  (b)R>r  (c)R=r  (d)R=2r
Give reason.

Guys... when a light ray undergoes refractions its frequency as well as the coour DOES NOT CHANGE..its a misconception that as wavelength changes colour changes. Colour depends upon the frequency...correct me if im wrong

State the principle of a machine.

With respect to cathode ray tube give reasons-
1.anode is kept at +ve potential with respect to cathode
2.the screen is coated with fluorescent material
3.a grid is kept in between cathode and anode

What is Newton's colour disc and what fact did it bring out??this experiment is essential for spectrum someone reply pls

A wire is turned red hot by passing electric current through it. Half of this heated wire is immersed in cold water.What will happen to the amount of heat produced per unit length in the second half?

How to find the weight of the pulley when effort and load are given?

On Concise Pg 163 Example 5: Shouldn't it be 512 Hz as well??

I need another favour due to my 2014 edition book.
Can someone please upload  the picture of page 214 - from 2017 edition.
Thanks in advance.