Advertisements
Advertisements
Question
A given wire is stretched to double its length. How will its resistance change?
Advertisements
Solution
When a given wire is stretched to double its length, its area of cross-section will be halved, so the resistance of wire will become four times.
RELATED QUESTIONS
Complete the following :-
(c)
Show how would you join three resistors, each of resistance 9 Ω so that the equivalent resistance of the combination is
1) 13.5
2) 6 Ω
Show with the help of diagrams, how you would connect three resistors each of resistance 6 Ω, so that the combination has resistance of (i) 9 Ω (ii) 4 Ω.
In parallel combination of resistances ______.
Two resistors having resistance 4𝛀 and 6𝛀 are connected in parallel. Find their equivalent resistance.
The circuit diagram Fig shows three resistors 2 Ω, 4 Ω and R Ω connected to a battery of e.m.f. 2 V and internal resistance 3 Ω. If main current of 0.25 A flows through the circuit, find:
- the p.d. across the 4 Ω resistor,
- the p.d. across the internal resistance of the cell,
- the p.d. across the R Ω or 2 Ω resistors
- the value of R.
A current of 2 A is passed through a coil of resistance 75 Ω for 2 minutes.
(a) How much heat energy is produced?
(b) How much charge is passed through the resistance?
Calculate the current flows through the 10 Ω resistor in the following circuit.
Three resistors of 1 Ω, 2 Ω and 3 Ω are connected in parallel. The combined resistance of the three resistors should be:
Two resistors having resistance 8 Ω and 12 Ω are connected in parallel. Find their equivalent resistance.
