Physics
Grade-9
Easy
Question
Two wires of the same material have the same length, but their radii are in the ratio of 5:3. They are combined in series, where the resistance of the thicker wire is 12 ohms. Calculate the total resistance of the combination
- 40 Ω
- 12 Ω
- 33.3 Ω
- 0.03 Ω
Hint:
The total resistance of the combination of resistors in series is RT= R1+R2
The correct answer is: 33.3 Ω
When two wires of radii in the ratio of 5:3 are combined in series, where the resistance of the thicker wire is 12 ohms, the resistance of the combination is 32 Ω.
- Given, the radii of the wire are in the ratio of 5:3 which is R2/R1
- We can write it as, R2/R1= 5/3, where R2= (5/3) R1
- The R1 given is the thicker wire with resistance of 12 Ω. So R2=
- Hence, their total resistance is RT= R1+R2, i.e. 12+20= 32 Ω
Related Questions to study
Physics
Resistors of resistances 10 Ω, 20 Ω, 30 Ω are connected in parallel so that the combination carries a current of 11 A. Potential difference across the combination is
Resistors of resistances 10 Ω, 20 Ω, 30 Ω are connected in parallel so that the combination carries a current of 11 A. Potential difference across the combination is
PhysicsGrade-9
Physics
Four resistors of 100 Ω each are connected in series across a battery of 500 V. What is the amount of current in the circuit?
Four resistors of 100 Ω each are connected in series across a battery of 500 V. What is the amount of current in the circuit?
PhysicsGrade-9
Physics
Four unequal resistors are connected in parallel with each other. Which one of the following statements is correct about this combination?
Four unequal resistors are connected in parallel with each other. Which one of the following statements is correct about this combination?
PhysicsGrade-9
Physics
Four unequal resistors are connected in series with each other. Which one of the following statements is correct about this combination?
Four unequal resistors are connected in series with each other. Which one of the following statements is correct about this combination?
PhysicsGrade-9
Physics
In parallel combination of resistors, the amount of current in the circuit
In parallel combination of resistors, the amount of current in the circuit
PhysicsGrade-9
Physics
In a series combination of resistors, the amount of current in the circuit
In a series combination of resistors, the amount of current in the circuit
PhysicsGrade-9
Physics
Equivalent resistance of the resistors connected in series is __________ individual resistances in the circuit.
Equivalent resistance of the resistors connected in series is __________ individual resistances in the circuit.
PhysicsGrade-9
Physics
Magnitude of current across each resistor in a series combination
Magnitude of current across each resistor in a series combination
PhysicsGrade-9
Physics
In a series circuit, the total resistance is greater than the largest resistance in the circuit.
In a series circuit, the total resistance is greater than the largest resistance in the circuit.
PhysicsGrade-9
Physics
Pick out the correct statement from the following about the parallel combination of resistors.
Pick out the correct statement from the following about the parallel combination of resistors.
PhysicsGrade-9
Physics
The equivalent overall resistance is smaller than the smallest parallel resistor in a parallel connection. This statement is ____.
The equivalent overall resistance is smaller than the smallest parallel resistor in a parallel connection. This statement is ____.
PhysicsGrade-9
Physics
What is the equivalent resistance of a series combination of three resistors?
What is the equivalent resistance of a series combination of three resistors?
PhysicsGrade-9
Physics
An electrician installs patio lights in a back yard. Which of the following will increase the efficiency of the wiring system to the back yard?
1- Bury the extension cord deep underground.
2- Use a shorter extension cord.
3- Use a longer extension cord.
4- Use compact fluorescent patio lights
An electrician installs patio lights in a back yard. Which of the following will increase the efficiency of the wiring system to the back yard?
1- Bury the extension cord deep underground.
2- Use a shorter extension cord.
3- Use a longer extension cord.
4- Use compact fluorescent patio lights
PhysicsGrade-9
Physics
30 Joules of energy enter a light bulb. 20 joules of energy are transformed into light, how much energy is dissipated as heat?
30 Joules of energy enter a light bulb. 20 joules of energy are transformed into light, how much energy is dissipated as heat?
PhysicsGrade-9
