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
Complete the following :-
(c)

What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series?
A wire that has resistance R is cut into two equal pieces. The two parts are joined in parallel. What is the resistance of the combination?
Two resistors, with resistance 5 Ω and 10 Ω respectively are to be connected to a battery of emf 6 V so as to obtain:
(i) minimum current flowing
(ii) maximum current flowing
(a) How will you connect the resistances in each case?
(b) Calculate the strength of the total current in the circuit in the two cases.
In the circuit given below:
(a) What is the combined resistance?
(b) What is the p.d. across the combined resistor?
(c) What is the p.d. across the 3 Ω resistor?
(d) What is the current in the 3 Ω resistor?
(e) What is the current in the 6 Ω resistor?
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.
The figure given below shows three resistors?
Their combined resistance is:
(a) `1 5/7`Ω
(b) `14` Ω
(c) `6 2/3` Ω
(d) `7 1/2` Ω
A resistor of 8 ohms is connected in parallel with another resistor X. The resultant resistance of the combination is 4.8 ohms. What is the value of the resistor X?
Which of the following combinations have the same equivalent resistance between X and Y?
A battery of e.m.f 16 V and internal resistance 2 Ω is connected to two resistors 3Ω and 6Ω connected in parallel. Find:
- the current through the battery.
- p.d. between the terminals of the battery,
- the current in 3 Ω resistors,
- the current in 6 Ω resistor.
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 particular resistance wire has a resistance of 3 ohm per meter. Find :
The total resistance of three lengths of this wire each 1.5 m long, in parallel.
An electrical appliance having a resistance of 200 Ω is operated at 200 V. Calculate the energy consumed by the appliance in 5 minutes in kWh.
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.

Calculate the current flows through the 10 Ω resistor in the following circuit.

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:
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.

Two resistors having resistance 8 Ω and 12 Ω are connected in parallel. Find their equivalent resistance.
