Download electricity

1
NRT INDIA
ELECTRICITY
ELECTRICITY
1.
Two bodies A and B are rubbed together and thus A is positively charged what type of charge B will acquire?
2.
When a body A is brought near to a positively charged body B, attraction is found. Now by bringing A near to
negatively charged body C, attraction is found. What type of chare A is having?
3.
What type of electrostatic force will act when a positively charged body is brought near to a negatively charged
body?
4.
What type of electrical force will act between two positively charged bodies?
5.
What type of will act between two negatively charged bodies.
6.
What do you mean by electrification of bodies?
7.
What is quantity of charge on an electron ?
8
What is quantity of charge on a proton ?
9.
What are the fundamental particles of an atom?
10.
Which of the particle among proton, electron, proton and neutron?
11.
Write ratio among the masses of electron, proton and neutron?
12.
How many fundamental particles are found in the nucleus of hydrogen?
13.
How many fundamental particles are found in the nucleus?
14.
What is the position of electrons is structure of an atom?
15.
What type of fundamental particles are found in a helium nucleus?
16.
There are 7 protons in the nucleus of an atom. How many electrons will there be ?
17.
There are 8 electron in an atom. How many protons will there be in its nucleus?
18.
A conductor has 11.2×10-19 coulomb positive charge. In normal condition hw many electrons are less or more
on it?
19.
A conductor has 8.0×10-19 coulomb negative charge. In normal condition, how many electrons are less or more
on it?
20.
Three electrons are excluded from a conductor. Write whether the conductor will acquire either positive or
negative charge? If charge on an electron is 1.6×10-19 coulomb, what will the magnitude of charge be?
21.
A conductor gains 10 electrons from another body. What type of charge will the conductor acquire?
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22.
ELECTRICITY
Objective type of question
Find the correct alternative
(i) In electrification the transference takes place of
(a) protons
(b) electrons
(c) neutrons
(d) both electrons and protons
(ii) Body acquire 9.6×10-19 coulomb charge, when two bodies are rebbed together. The second body
will acquire the charge –
(a) 9.6.2×10-19 coulomb positive charge
(b) 19.2×10-19 coulomb positive charge
(c) 9.6×10-19 negative charge
(d) none of these
(iii) There are 12 neutrons and 11 protons in the nucleus of an atom of an element. The number of electrons will
be
(a) 11
(b) 12
(c) 23
(d) 1
(c) free electrons
(d) none of these
(iv) The conduction in metals due to presence of
(a) protons
23.
(b) neutrons
Classify the following into conductors, semi-conductors and insulators brass, copper, mercury, paper, wax,
germanium, leather, distilled water, aqueous solution of ammonium chloride, gold, wood and coke..
24.
Explain on account of atomic model –
(i) Why the bodies are charged when rubbed together?
(ii) Why the produced charge on both the bodies is equal ?
25.
What are free electrons?
26.
What are conductors and insulators of electric chare?
27.
What is difference between conductors and insulators o account of atomic model?
28.
What do you mean by electrostatic induction? Explain with example.
29.
How a body is positively charged with electrostatic induction process?
30.
How a body is negatively charged by the process of electrostatic induction?
31.
Explain the charging of a body by induction process on account of modern electronic model.
32.
What do you mean by electric current? Write its unit.
33.
Write definition of ampere.
34.
Show the direction of electronic current in a Leclanche cell from positive terminal to negative terminal. Also
show the direction of conventional current.
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NRT INDIA
ELECTRICITY
35.
What is difference between the direction flow of current in an external circuit and internal circuit of a cell?
36.
What do you mean by potential difference? Write its unit.
37.
What is you mean by electromotive force of a cell?
38.
What is function of an electric cell in an electrical circuit?
39.
What type of conversion of energy in the following pars of an electric circuit
(i) electric cell
(ii) metallic wire
40.
What is the difference between ‘primary cell’ and ‘secondary cell’?
41.
What do you mean by ‘polarisation’ of a primary cell? Which of the substances are as depolarisers in Leclanche
cell and Danielcell?
42.
Draw a well labeled diagram of Leclanche cell and describe its working.
43.
Draw a diagram of a ‘dry cell’. Write chemical reactions.
44.
Draw a well labeled diagram of a Daniel cell and explain how polarisation is removed in this cell.
45.
Describe the working of a lead accumulator.
46.
3.5 ampere current is flowing through a conductor. Calculate the quantity of charge flown through the
conductor in one minute.
47.
200 milliampere current is flowing through a conductor, calculate the number of free electrons pasing through it
in one second. (Change on an electron = 1.6×10-19 coulomb).
48.
2.5×1018 free electrons are flowering per second through a wire of copper. Calculate the current through the
wire. (e = 1.6×10-19 coulomb).
49.
1.0 millisenond is required for neutralization o two copper spheres one is positive charged and the other is
negatively charge. During this time 200 micro coulomb charge is flown. Calculate the value of average current
in the wire.
50.
3.0 joule energy is lost in a conductor when 0.5 coulomb charge is flown through it. Calculate potential
difference across the conductor.
51.
The potential difference across a conductor is 1.5 volt. Calculate the amount of work done by a free electron in
flowing from one end to the other. (e = 1.6×10-19) coulomb).
Objective question
52.
The flow of electric current in a metallic wire due to
(a) protons
(b) ions
(c) neutrons
(d) electrons
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53.
The electric cell is a source of
(a) electrons
54.
(d) electric current
(b) only Cl– ions
(c) NH4− and Cl– ions
(d) free electrons.
(b) MnO2
(c) NH4Cl
(d) plaster of paris
(c) joule
(d) coulomb
The unit of electromotive force is
(a) volt
57.
(c) electrons charge
The depolarizer in a dry cell
(a) copper sulphate
56.
(b) electrical energy
The flow of electric current in the electrolyte solution of a Lecloanche cell is by
(a) only NH4− ions
55.
ELECTRICITY
(b) ampere
Name the instrument through which the current is measured. In an electric circuit a resistance wire is joined
with a cell. Draw electric circuit diagram.
58.
Which of the electrical measuring instrument measures the potential difference? A resistance wire is connected
with a cell. How will you connect this circuit with the instrument? Draw circuit diagram.
59.
Show how will the above instruments be connected in the Fig
+
R1
R2
R3
60.
What is relationship between potential difference and current flowing through a conductor?
61.
Write Ohm’s law and formula related to it. On what factor the resistance of a conductor depends?
62.
What do you mean by the resistance of the conductor? Draw electric circuit diagram to measure it.
63.
On what factors the potential difference of a conductor depends?
64.
Draw diagrams of ohmic circuits and a non-ohmic circuit (only graph is required).
65.
What do you mean by ‘specific resistance’ of substance? On what factors does it depend?
66.
The radii of two wires of same length and material are r1 and r2. Find the ratio between the resistance of these
wires.
67.
A uniform wire is cut into two pices of lengths l1 and l2. Find the ratio between the resistance of these pices.
68.
Why the resistance wires are not made of copper?
69.
Two resistances P and Q are connected in series. Drive and expression for equivalent resistance.
70.
Two resistances P and Q are connected in parallel. Drive and expression for equivalent resistance.
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ELECTRICITY
71.
What do you mean by internal resistance of a cell? Write formula for it.
72.
A potential difference of 200 is applied across a resistance of 400Ω in a light bulb. Calculate the current and the
electric energy dissipated per second.
73.
What are the factors on which the resistance of a give conductor depends. Define the resistivity of a material.
74.
A battery of 6 V is connected in series with three resistors 12Ω, 6Ω, 4Ω (Fig) Is the current passing through
each of the resistors the same? Calculate the potential difference across each resistor.
12Ω
6Ω
4Ω
6V
75.
In the circuit shown in Fig calculate (a) the current flowing through the arms AB, AC and CDE; (b) the
potential difference across AB, CD and DE.
C
D
E
6Ω
4Ω
A
B
12Ω
1.5 V
76.
The ratio between diameters of two wires of equal lengths is 2 : 3. If resistance of one wire is 3.6 Ω. Find
resistance of the second wire.
77.
The resistances of two wires of different materials of same lengths and diameters are 2Ω and 2.5Ω. If specific
resistance of first wire is 4.4×10-7 ohm metre, find the specific resistance of second wire.
78.
The specific resistance of nichrome is 9.5×10-7 ohm ×metre. Find the length of the wire of this material of
resistance 19 ohm and diameter 0.5 mm.
79.
Three resistance 1Ω, 2Ω and 6Ω are connected (i) in series and (ii) in parallel and with a cell of e.m.f. 1.5V.
Calculate the current flowing in the circuit in each case.
80.
P = 6Ω
In Fig calculate
(i) Resistance of Q
2A
(ii) Current through P.
(iii) Potential difference across A and B.
A
Q
B
1.5 A
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81.
ELECTRICITY
In Fig the e.m.f. of the battery is 6.25 V and internal resistance is 0.1 ohm. Calculate :(i) the readings of ammeters A1, A2 and A3.
+ e = 6.25 V
(ii)Reading of voltmeter V.
A1
A2
3Ω
A3
V
+
82.
83.
In Fig calculate
(i) total external resistance.
(ii) current through cell.
(iii) potential difference between B and C.
A
(iv) the potential difference between terminal of the cells.
E 1.5 V
r = 1Ω
2Ω
B
4Ω
C
4Ω
Write the formula for consumed electrical energy in a circuit, in terms of
(i) potential difference and current
(ii) Potential difference and resistance
(iii) Current and resistance
84.
Write formula of heat produced by flowing electric current through a conductor.
85.
Two resistors R1 and R2 are connected in parallel to a cell. What will the ratio between the produced heat in
these resistors in the same time interval?
86.
Prove that the power of an electric bulb is inversely proportional to the resistance of a filament of the bulb.
87.
Write relation between ‘K.W.H’ and ‘Joule’
88.
An electric heater is marked as ‘5ooW – 240volt’. What does it mean?
89.
Which of the effect of electric current is used in an electric bulb?
90.
Why nitrogen or argon gas is filled in electric bulb?
91.
Two bulbs consist of filament of the same material and of same length but thickness of one filament is more
than the other, which of the bulb will have more power if these are used on same voltage?
92.
Why a fuse wire is used in an electric circuit?
93.
What is function of the following in simple house wiring ?
(i) watt hour metre
94.
(ii) main switch
(iii) main fuse
Draw a diagram of fluorescent light tube. Why a fluorescent light tube is more useful then an electric bulb?
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95.
ELECTRICITY
While using a galvanometer as (i) ammeter (ii) voltmeter, why the external resistances are used with the coil of
galvanometer?
96.
Why an ammeter is connected in series in an electrical circuit?
97.
Why a voltmeter is connected in parallel in an electric circuit?
98.
Describe in short ‘watt-hour-meter’.
99.
Two resistors of 2 ohm and 10 ohm are connected to a cell(i) In series (ii) In parallel. Which of the resistor will
be more heated?
100.
An electric bulb is marked ‘25W – 250 volt’. Calculate the strength of current flowing through the bulb and
resistance of the filament when is used at 250 volt mains.
101.
Compare the resistance of two bulbs of 25 watts and 100 watts, is their voltage the same.
102.
Calcualte the consumed electrical energy in K.W.H. and in joules while an electric bulb of power 250 watt is
rated for 6 hours
103.
Calculate the quantity of heat produced while using an electric heater of power 1.5 KW for 30 minutes.
104.
In a house 15 bulbs of 40 W, 5 bulbs 100W, 5 fans of 80W and heater of 1.0 KW are used. The bulbs are used
for 4 hours, the fans for 10 hr and heater for one hour daily. The voltage of mains is 220 volts. Calculate
(i) Power of electric installation of house.
(ii) Cost of consumed electric energy in a week at the rate of 60 paisa per unit.
105.
KWH. is unit of
(a) Electric potential
106.
(c) Energy power
(d) Charge
The power of electrical substation is 200 MW. The electrical energy produced daily form this station will be
(a) 200 MWH
107.
(b) Electric potential
(b) 4800 MWH
(c) 4800 MW
(d) 4800 Joule
The cost of consumed electric energy for domestic use is 60 paise per unit.
(a) 1 ampere
(b) 1 volt
(c) 1 Joule
(d) 1 K.W.H.
NRT India , 14/32, RLB Road Near Munshi Pulia, Indira Nagar, Lucknow. Call: 0522-2714802, 9415905513, 8090510938
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