Why ice floats on water?

Finding specific latent heat of vaporisation (lv) (pure physics)

Take note that the question is looking for specific latent heat of vaporisation during boiling. Hence information of mass m1 before heating is not relevant. There is no change of state of the water, it is merely the heating of the water (which involves specific heat capacity of water).

Solutions: Option D

Refer to the worked solution below.

Modification to ammeter to measure bigger current

Sensitivity of the ammeter means that how small a current the ammeter can measure.

Example, if the original set up is 0.2 A per division, and the modified set up can measure up to 0.1 A per division, so we say the latter one is more sensitive as it is able to measure smaller change in the currrent.