Download PHYSICS (Electricity) Class-X Q.1 What is represented by joule

PHYSICS (Electricity)
Class-X
Q.1 What is represented by joule/coulomb?
Q.2 Why are copper wires used as connecting wires?
Q.3 A wire of resistivity P is stretched to double its length. What is its new resistivity?
Q.4 What is the resistance of connecting wire?
Q.5 What is the resistance of an ammeter?
Q.6 What is the resistance of a Voltmeter?
Q.7 Which has more resistance: 100W bulb or 60W bulb?
Q.8 How will you join three resistances, each of 2ohm so that the effective resistance is 3ohm?
Q.9 What happens to the current in a circuit if its resistance is doubled?
Q.10 What happens to the resistance of a circuit if the current through it is doubled?
Q.11 How does the resistance of a wire depend upon its radius?
Q.12 Two wires are of the same length, same radius, but one of them is of copper and the other is
of iron. Which will have more resistance?
Q.13 Two wires of same material and same length have radii r1 and r2. Compare their resistances.
Q.14 Given three resistors each of resistors R. How will you combine them to get the
( i ) maximum and (ii) minimum effective resistance? What is the ratio of the maximum to
minimum resistance?
Q.15 A wire of length L and resistance R is stretched so that its length its doubled.
How will its (a) Resistance change (b) Resistively change ?
Q.16 Two students perform the experiments on series and parallel combinations of
two given resistors R1 and R2 and plot the following V-I graphs.
Which of the graphs is (are) correctly labeled in terms of the words ‘series’ and parallel’ Justify your
answer.
Chapter- Electricity (class-X)
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Q.17 A household uses the following electric appliances :
(i) Refrigerator of rating 400W for ten hours each day.
(ii) Two electric fans of rating 80W each for twelve hours each day.
(iii) Six electric tubes of rating 18W each for 6 hours each day.
Calculate the electricity bill of the household for the month of June if the cost per unit of electric
energy is Rs. 3.00.
Q.18 Ammeter burns out when connected in parallel. Give reasons.
Q19. An electric geyser has the ratings 2000W,220V marked on it.What should be the
minimum current rating, that may be required for safe use of this geyser?
Q20. A wire of uniform thickness with a resistance of 27 is cut into three equal pieces and they
are joined in parallel. Find the resistance of the parallel combination.
Q.21 When a 10 V battery is connected across an unknown resistor, there is a current of 2 mA in
the circuit. Find the value of the resistance of the resistor.
Q22.Two electric bulbs are marked 60 W, 220V and 100 W, 220 Volt respectively. Which one has a
higher resistance?
Q23. A wire of resistivity ‘P’ is stretched to double its length. How does it affect the (a) resistance
(b) resistivity?
Q24.Two wires are of the same material but of different lengths and area of cross section. Will their
resistivity be the same or different? Give reason.
Q25.Draw a schematic diagram of a circuit consisting of a battery of five 2V cells, a 5 ohm resistor,
a 10 ohm resistor, a15 ohm resistor & a plug key all in series. Calculate current passing through the
above circuit when the key is closed.
Q26.Two bulbs are rated 100 W, 120 V and 10W, 120V respectively. They are connected in parallel
across a 120V source. Find the current in each bulb. Which bulb will consume more energy?
Q27.Two identical resistors, each of 2 ohm, are connected in turn (i) in series (ii) in parallel, to a
12V battery. Calculate the ratio of resistances consumed in the two cases.
Q28.What is the (a) highest (b) lowest total resistance, that can be secured by combinations of four
coils of resistances 4 ohm, 8 ohm, 12 ohm and 24 ohm?
Q29.What is the potential difference between the ends of a conductor of 16 ohm resistance ,
when a current of 2.5 A flows through it?
Q30.State the law which relates the current in a conductor to the potential difference across its
ends. Also draw the graph for the law.
Q31. State Ohm’s law .what is the necessary condition for a conductor to obey Ohm’s law.
Q32. A given wire is stretched to double its length. How will its resistance change?
Q33. Find the potential difference required to pass a current of 0.2 A in a wire of resistance 20
Q34. What length of copper wire of resistivity 1.7 x10-8
m and radius 1mm is required so that
its resistance is 1
Q35. A wire of 9
resistance having 30 cm length is tripled on itself. What is its new resistance?
Chapter- Electricity (class-X)
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Q36.
(i)
(ii)
Calculate the effective resistance in each case when R1= 12 ohm and R2= 15 ohm
Calculate the total value of current in each circuit when it is attach to a battery of
12V
Q37. (i)Draw a schematic diagram of a circuit consisting of a battery of six 2V cells, a 5ohm
resistor, a 12ohm resistor, a 15ohm resistor, and a plug key all connected in series.
(ii)Calculate the electric current passing through the above circuit when the key is closed.
Q38. (a)Why are electric bulbs filled with chemically inactive nitrogen or argon?
(b) What is meant by the statement that the rating of a fuse in a circuit is 5 A?
Q39. A resistor of 6 is connected in series with another resistor of 4 . A potential difference of
20V is applied across the combination. Calculate the current in the circuit and the potential
difference across 6 resistor.
Q40. Find out the reading of ammeter and voltmeter in the circuit given below :
Chapter- Electricity (class-X)
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