Advertisements
Advertisements
प्रश्न
Four resistors each of resistance 2Ω are connected in parallel. What is the effective resistance?
उत्तर
R1 = 2 ohm
R2 = 2 ohm
R3 = 2 ohm
R4 = 2 ohm
`1/R=1/R_1+1/R_2+1/R_3+1/R_4`
=`1/2+1/2+1/2+1/2=2`
R = 0.5 ohm
APPEARS IN
संबंधित प्रश्न
Complete the following :-
(c)
Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of 9 Ω.
An electric heater which is connected to a 220 V supply line has two resistance coils A and B of 24 Ω resistance each. These coils can be used separately (one at a time), in series or in parallel. Calculate the current drawn when:
(a) only one coil A is used.
(b) coils A and B are used in series.
(c) coils A and B are uses in parallel.
Which of the following combinations have the same equivalent resistance between X and Y?
What are the advantages of a parallel connection?
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.
How does the resistance of a metallic wire depend on the length of wire?
A piece of wire having a resistance R is cut into five equal parts.
- How will the resistance of each part of the wire change compared with the original resistance?
- If the five parts of the wire are placed in parallel, how will the resistance of the combination change?
- What will be ratio of the effective resistance in series connection to that of the parallel connection?
Two resistors when connected in parallel give the resultant resistance of 2 ohms, but when connected in series the effective resistance becomes 9 ohms. Calculate the value of each resistance.
A coil in the heater consumes power P on passing current. If it is cut into halves and joined in parallel, it will consume power: