Advertisements
Advertisements
Question
The equivalent resistance of a parallel combination of two resistors of 30 Ω and 60 Ω is ______________.
Options
90 Ω
2 Ω
20 Ω
1800 Ω
Advertisements
Solution
The equivalent resistance of a parallel combination of two resistors of 30 Ω and 60 Ω is 20 Ω.
APPEARS IN
RELATED QUESTIONS
With a neat labelled diagram and derive the equation for three resistances connected in parallel.
Show how you would connect two 4 ohm resistors to produce a combined resistance of (a) 2 ohms (b) 8 ohms.
Which of the following arrangement, A or B, has the lower combined resistance?

A 4 Ω coil and a 2 Ω coil are connected in parallel. What is their combined resistance? A total current of 3 A passes through the coils. What current passes through the 2 Ω coil?
Explain with the help of a labelled circuit diagram, how you will find the resistance of a combination of three resistors of resistances R1, R2 and R3 joined in parallel.
Are the lights in your house wired in series?
State how are the two resistors joined with a battery when potential difference is same across each resistor.
In parallel combination of resistances ______.
Five resistors, each 3 Ω, are connected as shown in Fig. Calculate the resistance
- between the points P and Q.
- between the points X and Y.
What are the advantages of a parallel connection?
Solve the following question:
In an electric circuit, two resistors of 12 0 each are joined in parallel to a 6 V battery. Find the current drawn from the battery.
How does the resistance of a metallic wire depend on the length of wire?
In the figure below, the ammeter A reads 0.3 A. Calculate:
(i) the total resistance of the circuit
(ii) the value of R
(iii) the current flowing through R.

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 devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is:
The least resistance obtained by using 2 Ω, 4 Ω, 1 Ω and 100 Ω is:
Assertion: When a battery is short circuited, the terminal voltage is zero.
Reason: In a short circuit, the current is zero.
Two V-I graphs A and B for series and parallel combinations of two resistors are as shown. Giving reason state which graph shows (a) series, (b) parallel combination of the resistors.

Four resistors each of resistance 5 Ω are connected in parallel. What is the effective resistance?
