Advertisements
Advertisements
प्रश्न
A given metallic wire of resistance R is doubled on itself. What will be its new resistance?
Advertisements
उत्तर
When a given metallic wire is doubled on itself, its length is reduced to half, but its area of cross-section gets doubled. So, the resistance of the wire will become one-fourth i.e., the new resistance of wire will be R/4 (or 0.25 R).
संबंधित प्रश्न
In series combination which remains constant?
(a) Voltage
(b) Current
(c) Both current and voltage
(d) Both are variables
Name the following substances:
(i) Showing low resistivity,
(ii) Showing very high resistivity,
(iii) Showing moderate resistivity.
Three resistors of 6.0 Ω, 2.0 Ω and 4.0 Ω are joined to an ammeter A and a cell of emf 6.0 V as shown in the following figure. Calculate :
- the effective resistance of the circuit.
- the reading of ammeter.
When do you say that the resistors are connected in this way? Draw a circuit diagram.
How does the resistance of an alloy, vary with temperature?
How does the resistivity of an alloy such as constantace depends on temperature.
Define the term resistivity and state its S.I. unit. Which will have higher resistivity a conductor or an insulator.
State expression for Cells connected in parallel.
Write an expression for calculating electrical power in terms of current and resistance.
Calculate the equivalent resistance between the points A and B for the following combination of resistors:
