Important Questions for CBSE Class 10 Science Chapter 12 - Electricity 1 Mark Question


CBSE Class 10 Science Chapter-12 Electricity – Free PDF Download

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CBSE Class 10 Science Chapter-12 Electricity Important Questions

CBSE Class 10 science Important Questions Chapter 12 – Electricity


1 Mark Questions

1. Which two circuit components are connected in parallel in the following circuit diagram?
(a) 
(b) 
(c) 
(d) 

Ans. 


2. A metallic conductor has loosely bound electrons called free electrons. The metallic conductor is
(a) negatively charged
(b) positively charged
(c) neutral
(d) Either positively charged or negatively charged
Ans. (c) neutral


3. Which of the following expressions does not represent the electric power in the circuit?
(a) VI
(b) 
(c) 
(d) 
Ans. (b) 


4. Resistivity of a metallic wise depends on
(a) its length
(b) its shape
(c) its thickness
(d) nature of material
Ans. (d) nature of material


5. If the current I through a resistor is increased by 100% the increased in power dissipation will be (assume temperature remain unchanged)
(a)100%
(b) 200%
(c) 300%
(d) 400%
Ans. (c) 300%


6. For the circuit arrangement shown below, a student would observe.

(a)Some reading in both ammeter and voltmeter.
(b)No reading in either the ammeter or the voltmeter.
(c)Some reading in the ammeter but no reading in the voltmeter.
(d)Some reading in the voltmeter but no reading in the ammeter.
Ans. (c) Some reading in the ammeter but no reading in the voltmeter.


7. A wire of resistance R is cut into five equal pieces. These pieces are connected in parallel and the equivalent resistances of the combination are. Then the ration  is
(a)
(b) 5
(c) 
(d) 25
Ans. (d) 25


8. The resistance of the conductor is R. If its length is doubled, then its new resistance will be
(a) R
(b) 2R
(c) 4R
(d) 8R

Ans. (c) 4R


9. A student carries out an experiment and plots the V-I graph of three samples of nichrome wire with resistances respectively as shown in the figure. Which of the following is live?
Ans. 


10. The nature of the graph between potential difference and the electric current flowing through a conductor is
(a)parabolic
(b) circle
(c) straight line
(d) hyperbolic
Ans. (c) straight line


11. An electric heater is salted at 1500w. How much heat is produced per hour?
(i) 5400 J
(ii) 54000 J
(iii)
(iv) 
Ans. (iv) 


12. A student says that the resistance of two wires of same length and same area of cross section is same. This statement is correct if
(a) Both wires are of different materials
(b) Both wires are made of same material and are at different temperature.
(c) Both wires are made of same material and are at same temperature.
(d) Both wires are made of different materials and are at the same temperature.
Ans. (c) Both wires are made of same material and are at same temperature.


13. In an experiment ohms law a student obtained a graph as shown in the diagram. The value of resistance of the resistor is
 

Ans.  


14. Work done to move 1coulomb charge from one point to another point on a charged conductor having potential 10volt is
(a) 1 Joule
(b) 10 Joule
(c) zero
(d) 100 Joule
Ans. (c) zero


15. Three resistors are shown in the figure. The resistance of the combination is

Ans. 


16. Name a device that helps to maintain a potential difference between across a conductor.
Ans. Battery.


17. What determines the rate at which energy is delivered by a current?
Ans. Electric power determines the rate at which energy is delivered by a current.


18. A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio R/R’ is:
(a) 1/25
(b) 1/5
(c) 5
(d) 25
Ans. (d) 25


19. Which of the following terms does not represent electrical power in a circuit?
(a) 
(b) 
(c) VI
(d) 
Ans. (b) 


20. An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power
consumed will be:
(a) 100 W
(b) 75 W
(c) 50 W
(d) 25 W
Ans. (d) 25 W


21. Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference.
The ratio of heat produced in series and parallel combination would be:
(a) 1:2
(b) 2:1
(c) 1:4
(d) 4:1
Ans. (c) 1:4


22. A wire of resistance R is bent in form of a closed circle, what is the resistance across a diameter of the circle?
Ans. 1/R’=1/(R/2)+1/(R/2) R’=R/4


23. A charge of 6 C is moved between two points P and Q having, potential 1OV and SV respectively. Find the amount of work done.
Ans. W=q( )= 6(10-5)=30 joule


24. Name the physical quantity whose SI unit is JC
Ans. Potential


25. Why are copper wires used as connecting wires?
Ans. The electrical resistivity of copper is low.


26. A wire of resistivity p is stretched to double its length. What is its new resistivity?
Ans. It remains same because resistivity depends on nature of material.


27. What is the resistance of connecting wire?
Ans. The resistance of a connecting wire, which is made of good conductor, is negligible.


28. What is the resistance of an ammeter?
Ans. The resistance of an ammeter is very small and for an ideal ammeter, its value is zero.


29. What is the resistance of a Voltmeter?
Ans. The internal resistance of an ideal voltmeter is infinity and the internal resistance of an ideal ammeter is zero.