Answer:
<h2><u>Rheostat:</u></h2>
=> Rheostat is an electric device used as a variable resistance, like the regulator of the fan. It is used to change the electric resistance in the electric circuit.
<h2><u>Principle / Rule:</u></h2>
=> Rheostat works on the principle of Ohm’s law. Ohm’s law states that current in a circuit is inversely proportional to the resistance at the given temperature.

Answer:
n = 1.76
Explanation:
According to the rule of ( n1 sin theta1 = n2 sin theta2 )
we know both angles so we insert them to the law and apply n1 = 1
so 1/2 = n2 sin 62 and we get the final answer
Answer:
Base quantities are the minimum numbers of the physical quantities. Base quantities are defined as the physical quantities which can not be defined in terms of other physical quanities. There are seven base quantities. Physical Quantitie Units Derived Quantities are defined as those physical quantities which are derived from the base quantities.
Explanation:
A physical quantity is a property of a material or system that can be quantified by measurement. A physical quantity can be expressed as the combination of a numerical value and a unit. For example, the physical quantity mass can be quantified as n kg, where n is the numerical value and kg is the unit. A physical quantity possesses at least two characteristics in common, one is numerical magnitude and other is the unit in which it is measured.
Distinguish between a basic physical quantity and a derived physical quantity giving an example of each. Answers. Basic physical quantities are quantities which can be obtained without derivation. e.g Temperature. While derived physical quantities are quantities which can only be obtained from other physical quantities.
Answer:
2.521 (A); 14.0924 (V)
Explanation:
more info in the attachment, the answers are marked with red colour.