In Burning of coal, burning of wood and Heating of Potassium Chlorate there will be some sort of chemical change, but Heating of a Platinum crucible is a physical change.

For balancing the weight of ring, you need to put your finger or any solid object inside the ring so that you will be able to sustain their own weight because they are not able to sustain their own weight.so its centre of mass lies outside the body.

As  the  capacitance  is  charged  by the  factor  equal  to  the  value  of dielectric constant, Hence, C’ = kC = 7C

Semiconductors are the basic materials used in the present solid state electronic devices like diode, transistor, ICs, etc. 2. Lattice structure and the atomic structure of constituent elements decide whether a particular material will be insulator, metal or semiconductor. Semiconductors are elemental (Si, Ge) as well as compound (GaAs, CdS, etc.). Silicon, Germanium, Gallium Arsenide are semiconductors, but Quartz is an insulator.

P= I^2.R where, I= Current, P= Electric Power, R=Resistance. Here all the resistance is put in parallel combination and in parallel combination the value of Resistance decreases and dissipation of power increase, hence 3 times more power will be dissipated(3P).

p type of semiconductor is obtained when Silicon is doped with a trivalent impurity like Aluminium. Aluminium is a p-type dopant, which means that when a semiconductor i.e. silicon is doped with aluminium, it creates a hole (positively charged carrier) by accepting an electron from the silicon atom. Electrical conductivity of semiconductors increasesand resistivity remains the same

Deficiency of Vitamin C causes Scurvy, Swelling of gums etc.Vitamin K causes Non-clotting of blood ,Vitamin D causes Rickets in children and Osteomalasia in adults, Vitamin B 1 causes Beriberi,B2 causes Cracking of skin,reddish eye,cracking of tongue,B3 causes Whitening of hair ,mentally retardness ,B5 causes Pallagra or 4D syndrome,B6 causes Anemia,skin disease ,B7 causes Paralysis,hair falling,B11 causes Dysentery and B12 causes Jaundice and Teroile Glutemi

Syngamy, also known as fertilisation occurs between the male and female gametes. Syngamy may occur either externally, outside the body of organisms or internally, inside the body. Syngamy leads to formation of a specialised cell called diploid zygote.