Multiple Choice Questions in Science: January 2014

Choose Appropriate Alternative

The SI unit of electric charge is...

[A] ampere [B] volt [C] watt [D] coulomb

How many electrons will be there in 1.6 C charge?
```
[A] 10¹⁷ [B] 10¹⁸ [C] 10¹⁹ [D] 10²⁰
```
1 μA = ______ mA.
```
[A] 10^-16[B] 10^-3 [C] 10³ [D] 10⁶
```
Which of the following materials has more number of free electrons?
```
[A] Copper [B] Glass [C] Rubber [D] Iron
```

According to Ohm's law...

[A] The resistance increases with the increase in current. 
[B] The resistance increases with the increase in voltage.
[C] The current increases with the increase in voltage. 
[D] The resistance and current both increase with the increase in voltage.

The formula for electric current is...

[A] I = Q.t [B] I = Q/t [C] I = t/Q [D] I = W.t

2 A current is passed through a conducting wire for 1 min. How much charge will flow through the wire?
```
[A] 2 C [B] 30 C [C] 60 C [D] 120 C
```
In an electrical appliance, current of 4.8 A is passed. The number of electrons passing through it in 1 sec will be...
```
[A] 0.33 x 10¹⁹ [B] 3.3 x 10¹⁹ [C] 3 x 10¹⁹ [D] 4.8 x 10¹⁹
```

Which of the following formulas represents voltage?

[A] Work/(current.time)      [B] Work.time/current 
[C] (Work).(electric charge) [D] (Work).(electric charge).(time)

The unit of electrical potential difference is...
```
[A] J [B] J/C [C] J.C [D] C/J
```
If the work done to move 3 C electric charge from one point to another point is 15 J, what will be the potential difference between these points?
```
[A] 3 V [B] 15 V [C] 5 V [D] 45 V
```
The resistance of a conducting wire is 10 Ω. How much electric current will flow by connecting it with a battery of 1.5 V?
```
[A] 0.15 mA [B] 1.5 mA [C] 15 mA [D] 150 mA
```

On which factors does the resistivity of a conducting wire depend?

[A] Length of wire [B] Cross-sectional area of wire 
[C] Volume of wire [D] Material of wire

If 5 equal pieces are made from a wire having resistance 5 Ω and then each piece is connected in parallel to others, then their equivalent resistance will be...
```
[A] 1/5 Ω [B] 1 Ω [C] 5 Ω [D] 25Ω 
```
The unit of resistivity is...
```
[A] Ω [B] Ω.m [C] Ω/m [D] m/Ω
```
What will be the equivalent resistance between points A and B of the following circuit?
```
[A] 1 Ω [B] 2 Ω [C] 5 Ω [D] 10 Ω
```
What will be the equivalent resistance between points A and B of the following circuit?
```
[A] 4 Ω [B] 8 Ω [C] 2 Ω [D] ⒠
```
What will be the equivalent resistance between points A and B of the following circuit?
```
[A] 2.5 Ω [B] 5 Ω [C] 12.5 Ω [D] 20 Ω
```

Which physical quantity has the unit kWh?

[A] Work [B] Electric power [C] Electric current [D] Electric potential

1 kWh = _____ joule.

[A] 3.6 x 10⁶ [B] 3.6 x 10³ [C] 3.6 x 10^-6 [D] 3.6 x 10^-3

An electric heater consumes 1.1 kW power when 220V voltage is applied to it. How much current will flow through it?
```
[A] 1.1 A [B] 2.2 A [C] 4 A [D] 5 A
```

What makes electric current flow through a solution?

[A] Only free electrons [B] Only positive ions 
[C] Only negative ions [D] Positive and negative ions

The distilled water acts as _____ for the electricity.

[A] conductor [B] insulator [C] semiconductor [D] none

The magnitude of electric force between the charges can be calculated using the law devised by...
```
[A] Coulomb [B] Ohm [C] Maxwell [D] Ampere
```

Free electrons are...

[A] in the first orbit [B] in any orbit 
[C] valence electrons [D] on the surface of the conductor

_____ discovered electrons.

[A] Ampere [B] Faraday [C] Thomson [D] Coulomb

1 mA = _____ A.
```
[A] 10 [B] 10^-1[C] 10^-2[D] 10^-3
```

In Volta's cell...

[A] electrical energy is converted to thermal energy.
[B] thermal energy is converted to electrical energy.
[C] chemical energy is converted to electrical energy.
[D] electrical energy is converted to chemical energy.

In Volta's cell _____ plate acts as cathode.

[A] copper [B] graphite [C] zinc [D] aluminium

The SI unit of resistance is...

[A] coulomb/sec [B] volt/ampere [C] ampere/volt [D] volt/joule

Which of the following has maximum resistivity?

[A] Tungsten [B] Nichrome [C] Aluminium [D] Diamond

Which of the following is a semiconductor?

[A] Germanium [B] Diamond [C] Graphite [D] Nichrome

The chemical equivalent of an atom is the ratio of...

[A] atomic mass to atomic radius [B] atomic radius to atomic mass 
[C] atomic mass to valency      [D] valency to atomic mass

Work done on an electric charge is stored in it as...

[A] potential energy [B] kinetic energy [C] thermal energy [D] nuclear energy

_____ is not essential to obtain electric current.

[A] Free electrons [B] Potential difference [C] Electric circuit [D] Potential

Who invented the simple electrochemical cell?
```
[A] Faraday [B] Edison [C] Volta [D] Coulomb
```

When resistors are connected in series...

[A] voltage drop is uniform               [B] current is uniform 
[C] voltage drop and current are uniform [D] neither of the two is uniform

When resistors are connected in parallel...

[A] voltage drop is uniform               [B] current is uniform 
[C] voltage drop and current are uniform [D] neither of the two is uniform

The equivalent resistance of three resistors of 6Ω, 12Ω and 12Ω connected in parallel is...
```
[A] 6Ω [B] 12Ω [C] 3Ω [D] 1/3Ω
```
Which of the following is not correct for electric work(W)?
```
[A] W = V.Q [B] W = V.I.t [C] W = I²Rt [D] W = I²RQ
```

_____ is not a unit of energy.

[A] joule [B] watt [C] watt.second [D] kWh

1 joule = ______.

[A] 1 watt.second [B] 1 watt/sec [C] 1 coulomb/sec [D] 1 unit

Which of the following is not correct?

[A] P = W/t [B] P = I²R [C] P = W.I [D] P = V.I

Silicon is a/an...

[A] conductor [B] insulator [C] semiconductor [D] superconductor

The equivalent resistance of the resistances connected in parallel is...

[A] smaller than the smallest resistance [B] larger than the largest resistance
[C] an average of all resistances       [D] algebraic sum of all resistances

1 unit of domestic electrical energy is...

[A] 1 joule [B] 1 watt.sec [C] 3.6 x 10⁶ joule [D] 3.6 x 10⁶kWh

Three resistances of equal magnitude are connected in parallel. The circuit current is 3 A. Then the current passing through each resistor is...
```
[A] 3 A [B] 1 A [C] 9 A [D] 1/3 A
```

How much total electric charge is present on 100 protons?

[A] 6 x 10^-19C [B] 6 x 10^-17C [C] 1.6 x 10^-19C [D] 1.6 x 10^-17C

Which of the following is a good conductor of electricity?
```
[A] Rubber [B] Glass [C] Plastic [D] Graphite
```
Which of the following is a bad conductor (insulator) of electricity?
```
[A] Copper [B] Graphite [C] Glass [D] Silver
```

Which of the following statements is true for electric current?

[A] The direction of conventional current and that of electrons is opposite.
[B] The direction of conventional current and that of electrons is same. 
[C] The direction of conventional current is random.
[D] Electron flow is random.

1 μA = ______ mA
```
[A] 10^-1 [B] 10^-2 [C] 10^-3 [D] 10³
```
1 mA = _____ μA
```
[A] 10^-1 [B] 10^-3[C] 10³ [D] 10⁶
```
How many electrons will carry 4.8 x 10^-16 C charge?
```
[A] 300 [B] 3000 [C] 480 [D] 4800
```
The unit coulomb/sec is expressed as...
```
[A] Ampere [B] Volt [C] Ohm [D] Watt
```
The SI unit of electric current is...
```
[A] Ohm [B] Coulomb [C] Ampere [D] Volt
```
If the electric charge passing through a conductor in 5 minutes is 480 C, the current flowing through it is...
```
[A] 96 [B] 2400 [C] 1.6 [D] 2.4
```
Which device is used to measure electrical potential difference?
```
[A] Ammeter [B] Voltmeter [C] Wattmeter [D] Galvanometer
```
The SI unit of electrical potential difference is...
```
[A] Ampere [B] Ohm [C] Weber [D] Volt
```
1.5 C charge is moved from a point at 5 V potential to a point at 8 V potential. What is the amount of work done in joule?
```
[A] 1.5 [B] 2.0 [C] 3.0 [D] 4.5
```
If the work done to move 4 C charge from one point to another point is 10 joule, what is the potential difference between those points?
```
[A] 2.5 V [B] 40 V [C] 14 V [D] 160 V
```

Which of the following is true?

[A] Joule = (volt/coulomb)  [B] Volt = (joule/coulomb)
[C] Coulomb = (volt/joule) [D] Coulomb = (joule x volt)

According to Ohm's law...

[A] Current increases linearly with increase in voltage.
[B] The current ---> voltage graph is a straight line.
[C] The ratio of voltage and current is constant.
[D] All three in A, B and C are correct.

The SI unit of resistance is...

[A] volt [B] volt.ampere [C] ampere/volt [D] volt/ampere

Which of the following materials has least resistance?
```
[A] Aluminium [B] Glass [C] Carbon [D] Silicon
```
1.5 A current flows through a resistor when it is connected to a circuit with 3 V potential difference. What is the value of resistance?
```
[A] 4.5Ω [B] 2Ω [C] 0.5Ω [D] 1.5Ω
```
When a 15V battery is connected across a resistor of 6Ω, the amount of charge passing through it per second is...
```
[A] 90 C [B] 2/3 C [C] 2.5 C [D] 9 C
```
If the resistance of a circuit is doubled and the applied potential difference is halved, the current passing through the circuit will ...
```
[A] become 1/4 of original  [B] become 1/2 of original
[C] become 4 times original [D] not change
```
If the resistance of a circuit is halved and the applied potential difference is doubled, the current passing through the circuit will ...
```
[A] become 1/4 of original  [B] become 1/2 of original
[C] become 4 times original [D] not change
```
A 200 m long wire has cross sectional area of 10^-6 sq. m and its material has resistivity of 10^-7Ω.m. What will be its resistance?
```
[A] 0.2Ω [B] 2Ω [C] 20Ω [D] 200Ω
```
When two resistors with resistances R₁ and R₂ are connected in series and parallel, their equivalent resistances are R₃ and R₄, respectively. Then...
```
[A] R₁R₂ = R₃R₄ [B] R₁R₃ = R₂R₄ [C] R₁R₄ = R₃R₂ [D] R₁R₂R₃R₄ = 1
```
When two resistors with resistance of 10Ω and 20Ω are connected in series with a 3 V battery, the current passing through the circuit will be...
```
[A] 0.1 A [B] 1 A [C] 2 A [D] 3 A
```
When two resistors of 6Ω and 6Ω are connected in parallel with a 12V battery, the current flowing through the circuit is...
```
[A] 1.0 A [B] 2.0 A [C] 4.0 A [D] 0.25 A
```

The kilowatt-hour is a unit of...

[A] electrical potential [B] electric power [C] electric energy [D] electric current

7.2 x 10⁹ joule = _____ units of electrical energy.
```
[A] 0.2 [B] 20 [C] 2000 [D] 5000
```
An electric lamp draws a current of 0.5 A when connected to a 9V battery. What is the power rating of the bulb?
```
[A] 4.5 W [B] 18 W [C] 41.5 W [D] 2.25 W
```
If an electric iron has power rating of 2 kW, the cost of energy consumed for 24 hours at the rate of Rs. 6 per unit is equal to...
```
[A] Rs. 48 [B] Rs. 144 [C] Rs. 72 [D] Rs. 288
```
How many joules of energy is transferred by an electric bulb of 60 W power rating in one minute?
```
[A] 60 [B] 1000 [C] 3600 [D] 6000
```
A bulb has rating 12 V, 1 A. How much energy is consumed by it in 10 minutes?
```
[A] 120 J [B] 1200 J [C] 720 J [D] 7200 J
```

Match the physical quantities in Part A with their units in Part B.

[A] 1-c, 2-a, 3-d, 4-b [B] 1-c, 2-b, 3-d, 4-a
[C] 1-b, 2-d, 3-c, 4-a [D] 1-b, 2-a, 3-d, 4-c

Match the physical quantity in Part A with formula in Part B.

[A] 1-c, 2-d, 3-a, 4-b [B] 1-b, 2-d, 3-a, 4-c
[C] 1-b, 2-c, 3-d, 4-a [D] 1-c, 2-b, 3-a, 4-d

Which of the following circuit symbol represents electric cell?
Which of the following circuit symbol represents a resistor?
What will be the equivalent resistance in the following circuit?
```
[A] 2 Ω [B] 3 Ω [C] 4 Ω [D] 6 Ω
```
What will be the equivalent resistance between points A and b in the following circuit?
```
[A] 1 Ω [B] 2 Ω [C] 3 Ω [D] 4 Ω
```
What will be the equivalent resistance between points A and b in the following circuit?
```
[A] 1 Ω [B] 2 Ω [C] 3 Ω [D] 4 Ω
```
Which of the following circuits has the lowest equivalent resistance?
```
[A] Figure 1 [B] Figure 2 [C] Figure 3 [D] Figure 4
```
Two resistors each of value R are connected in series in a circuit with V volt battery. If two more resistances each of magnitude R are connected in series in this circuit, the current in the circuit will...
```
[A] become double [B] become half [C] not change [D] become one fourth
```
In an electric circuit, three bulbs of 40W, 60W and 100W are connected in series. The voltage drop is maximum across ____ bulb.
```
[A] 40W [B] 60W [C] 100W [D] None
```
According to Ohm's law, voltage drop is inversely proportional to...
```
[A] I [B] 1/I [C] R [D] 1/R
```
A 2 kW heater works on domestic voltage main supply. What should be the current rating of the fuse?
```
[A] 2 A [B] 5 A [C] 10 A [D] 6 A
```
6 C charge is passing through an electric bulb in one minute. How much current will pass through it?
```
[A] 10 A [B] 1 A [C] 0.1 A [D] 0.01 A
```

On what does the heat produced in a resistance depend?

[A] Electric current passed          [B] Resistance 
[C] Time for which current is passed [D] All of these

The electric force between two charges, q₁ and q₂, is ______ proportional to the product of the magnitudes of the charges and _____ proportional to the square of the distance between them.
```
[A] directly, inversely [B] directly, directly 
[C] inversely, directly [D] inversely, inversely
```
The resistance of a conductor is R. The resistance of another conductor of identical material and equal length with twice the diameter is...
```
[A] R/4 [B] R/2 [C] 2R [D] 4R
```
Which of the following combinations of length(l) and cross-sectional area(A) will give a certain volume of copper the least resistance?
```
[A] l and A [B] 2l and A/2 [C] l/2 and 2A [D] none as the volume is same
```
A resistor R₁ dissipates power P when connected to a certain generator. If a resistor R₂ is inserted in series with R₁, the power dissipated by R₁...
```
[A] decreases [B] increases [C] remains the same [D] any of the above depending on R₁ and R₂
```
A resistor R₁ dissipates power P when connected to a certain generator. If a resistor R₂ is inserted in parallel with R₁, the power dissipated by R₁...
```
[A] decreases [B] increases [C] remains the same [D] any of the above depending on R₁ and R₂
```
A 20-V potential difference is applied across a series combination of a 10 Ω and a 30 Ω resistors. The current in the 10 Ω resistor is...
```
[A] 0.5 A [B] 0.67 A [C] 1 A [D] 2 A
```
Two identical resistors in parallel have an equivalent resistance of 2 Ω. If the resistors were in series, their equivalent resistance would be...
```
[A] 2 Ω [B] 4 Ω [C] 8 Ω [D] 16 Ω
```
A 12-V potential difference is applied across a series combination of four 6Ω resistors. The current in each resistor is...
```
[A] 0.5A [B] 2A [C] 8A [D] 18A
```
A 12-V potential difference is applied across a parallel combination of four 6Ω resistors. The current in each resistor is...
```
[A] 0.5A [B] 2A [C] 8A [D] 18A
```
If a charge of Q coulomb flows in a part of a circuit across which there is a potential difference of V volt then the energy change W in joule is given by...
```
[A] Q.V [B] Q/V [C] V/Q [D] Q²/V
```
```
[A][B][C][D]
```

ANSWERS

(1) D (2) C (3) B (4) A (5) C (6) B (7) C (8) C (9) A (10) B (11) C (12) D (13) D (14) A (15) B (16) D (17) A (18) C (19) A (20) A (21) D (22) D (23) B (24) A (25) C (26) C (27) D (28) C (29) C (30) B (31) D (32) A (33) C (34) A (35) D (36) C (37) B (38) A (39) C (40) D (41) B (42) A (43) C (44) C (45) A (46) C (47) B (48) D (49) D (50) C (51) A (52) C (53) C (54) B (55) A (56) C (57) C (58) B (59) D (60) D (61) A (62) A (63) D (64) D (65) A (66) B (67) C (68) D (69) C (70) C (71) A (72) A (73) C (74) C (75) C (76) A (77) D (78) C (79) D (80) C (81) B (82) A (83) B (84) B (85) B (86) B (87) A (88) B (89) C (90) B (91) B (92) C (93) D (94) A (95) A (96) C (97) A (98) C (99) A (100) C (101) A (102) B (103) A

Multiple Choice Questions in Science

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Tuesday, January 7, 2014

Chapter 4 : ELECTRICITY

Choose Appropriate Alternative

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