Class 10 Science|physics Conceptual's Questions for Electricity
Given below are the Class 10 Science Conceptual Questions for electricity
(a) Concepts questions
(b) Multiple choice questions
(c) Long answer questions
(d) Fill in the blank's
(e) True and False
Question 1
Give us the factors on which resistance of the conductors depends Solution
The resistance of a conductor depends
(a) Length
(b) Area of its cross-section
(c) Nature of the material
Question 2
Write down the difference between Ammeters and Voltmeters? Solution
Question 3
Why is Tungsten used almost exclusively for filament of electric lamps? Solution
Melting point of tungsten is very high so it is used for making filament of electric lamps
Question 4 What happens to resistance of the conductor? Solution
Question 5 What is the difference between Open circuits and closed circuits? Solution
Question 6 Why does the cord of an electric heater not glow while heating element does? Solution
The cord of electric Heater is made of cooper which has extremely low resistance due to this negligible resistance heat is produced in it
The heating element of an electric heater is made of nichrome wire; It glows because large amount of heat is produced due to its high resistance
Question 7 Why do we use copper wire as connecting wires in the circuit? Solution
This is because Copper has very low resistivity
Question 8 True and False Statements
(a) Series arrangement is used in domestic circuits
(b) Resistance of the wire is directly proportional to the length of the wire
(c) The graph between V and I is a straight line
(d) A thick wire of length L will have less resistance than the thin wire of same length and same material Solution
(a) False, Parallel arrangement are used in domestic circuits
(b) True
(c) True
(d) True
Question 9
What does an electric circuit mean? Solution
Combination of electrical devices connected by conducting wires is called an electric circuit.
Question 10
Define the unit of electric current. Solution
The rate of flow of charge is called electric current and its S. I. unit is ampere. One ampere current is defined as below:
"If one coulomb charge flows through a conductor per second the strength of current is called one ampere."
Question 11
Name a device that helps to maintain a potential difference across a conductor. Solution
Cell is the device that helps to maintain a potential difference, across a conductor.
Question 12
What is meant by saying that the potential difference between two points is 1 V? Solution
Potential difference of 1 volt means that the rate of doing work during transfer of per coulomb charge is joule.
Question 13
Will current flow more easily a thick wire or a thin wire of the same material, when connected to the same source? Why? Solution
The current will flow easily through the thick the wire because the resistance of thick wire is less than thin wire.
$R \propto \frac{1}{A}$
Question 14
Let the resistance of an electrical component remains constant while the potential difference across the two ends of the componenets decreases to half of its former value. What change will occur in the current through it? Solution
At constant temperature and resistance:
$V \propto I$
Question 15
Why are coils of electric toasters and electric irons, made of an alloy rather than a pure metal? Solution
Alloys have more resistance then constituent metals. So, they are heated up easily due to the heating effect of electric current.
Question 16
(a)Which among iron and mercury is a better conductor?
(b) Which material is the best conductor? Solution
(a) iron
(b) Silver.
Question 17
What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series? Solution
The equivalent resistance of resistances connected in parallel is less than even the smallest resistance connected in parallel, so large current is obtained in the ciruit for the same potential difference. Since, the equivalent resistance is less, therefore, loss of energy due to resistance of conductor is less. These are the advantages of connecting the resistances in parallel.
Question 18
Why does the cord of an electric heater not glow while the heating element does ? Solution
We know, $H = I^2 Rt$
$H \propto\ R$
The resistance of heating elements very high, so more electrical energy is converted into heat energy, hence it glows. But the cord has very low resistance, so it does not glow.
Question 19
What determines the rate at which energy is delivered by a current? Solution
Electrical power determines the rate at which energy is delivered by a current.
Question 20
Which of the following represents voltage?
(a) $\frac {\text {Work done}}{\text {Current} \times \text {Time}}$
(b) $\text{Work done} \times \text{Charge}$
(c) $ \frac {\text {Work done} \times \text{Time}}{\text {Current}}$
(d) $\text{Work done} \times \text{Charge} \times \text{Time}$ Solution
(a)
