
The purpose of a rheostat is:
A. To increase the magnitude of current only
B. To decrease the magnitude of current only
C. To increase or decrease the magnitude of current only
D. None of these
Answer
427.5k+ views
2 likes
Hint:In electrical circuits, a rheostat is an electrical device which is used to change overall resistance of a circuit without changing any other effects in the circuit and in terms of its construction it’s very similar to the potentiometer.
Complete answer:
Let us first understand the working of a rheostat in brief. A rheostat is also known as a variable resistor where we can change the resistance of the circuit and its generally used for controlling the amount of current flowing in the circuit. It’s constructed as two terminals where one terminal is fixed and the other one can move between its two ends.
This moving terminal can be chosen in a desired way to change the resistance of the circuit and when it’s chosen in a way such that resistance is large, it decreases the current in the circuit and when it’s chosen in a way such that resistance is low then current in the circuit is increased. So, a rheostat can increase as well as decrease the current.
Hence, the correct option is C.
Note: It should be remembered that the wires which are used to make a rheostat is generally one which has a constant or negligible change in its resistivity over a wide range of temperature and these wires are such as constantan and manganin.
Complete answer:
Let us first understand the working of a rheostat in brief. A rheostat is also known as a variable resistor where we can change the resistance of the circuit and its generally used for controlling the amount of current flowing in the circuit. It’s constructed as two terminals where one terminal is fixed and the other one can move between its two ends.
This moving terminal can be chosen in a desired way to change the resistance of the circuit and when it’s chosen in a way such that resistance is large, it decreases the current in the circuit and when it’s chosen in a way such that resistance is low then current in the circuit is increased. So, a rheostat can increase as well as decrease the current.
Hence, the correct option is C.
Note: It should be remembered that the wires which are used to make a rheostat is generally one which has a constant or negligible change in its resistivity over a wide range of temperature and these wires are such as constantan and manganin.
Recently Updated Pages
Express the following as a fraction and simplify a class 7 maths CBSE

The length and width of a rectangle are in ratio of class 7 maths CBSE

The ratio of the income to the expenditure of a family class 7 maths CBSE

How do you write 025 million in scientific notatio class 7 maths CBSE

How do you convert 295 meters per second to kilometers class 7 maths CBSE

Write the following in Roman numerals 25819 class 7 maths CBSE

Trending doubts
A boat goes 24 km upstream and 28 km downstream in class 10 maths CBSE

The British separated Burma Myanmar from India in 1935 class 10 social science CBSE

The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths

What are the public facilities provided by the government? Also explain each facility

Difference between mass and weight class 10 physics CBSE

SI unit of electrical energy is A Joule B Kilowatt class 10 physics CBSE
