Download Jee 2014 Booklet6 Hwt Dc Circuits PDF

TitleJee 2014 Booklet6 Hwt Dc Circuits
TagsElectric Current Series And Parallel Circuits Electrical Resistivity And Conductivity Electrical Resistance And Conductance
File Size603.7 KB
Total Pages18
Document Text Contents
Page 1

Vidyamandir Classes

VMC/DC Circuits 73 HWT-6/Physics

DATE : TIME : 40 Minutes MARKS : [ ___ /15] TEST CODE : DC CR [1]

START TIME : END TIME : TIME TAKEN: PARENT’S SIGNATURE :

 This test contains a total of 15 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. If a wire is stretched to make it 0 1. % longer, its resistance will :

(A) increase by 0 2. % (B) decrease by 0..2%

(C) decrease by 0.05% (D) increase by 0.05%

2. A conductor wire having 2910 free electrons / m3 carries a current of 20A. If the cross-section of the wire is 1mm2, then the drift

velocity of electrons will be :

(A) 3 16 25 10. ms  (B) 5 11 25 10. ms  (C) 3 11 25 10. ms  (D) 4 11 25 10. ms 

3. A resistor has a colour code of green, blue, brown and silver. What is its resistance?

(A) 5600Ω 10% (B) 560 Ω 5% (C) 560 Ω 10% (D) 56 Ω 5%

4. The resistance of a 10m long wire is 10Ω . Its length is increased by 25% by stretching the wire uniformly. Then the resistance of
the wire will be :

(A) 12 5 Ω. (B) 14 5 Ω. (C) 15 6 Ω. (D) 16 6 Ω.

5. Find the true statement.
(A) Ohm's law is applicable to all conductors of electricity
(B) In an electrolyte solution, the electric current is mainly due to the movement of electrons
(C) The resistance of an incandescent lamp is lesser when the lamp is switched on
(D) specific resistance of a wire depends upon the dimension

6. The masses of the three wires of copper are in the ratio 5 : 3 : 1 and their lengths are in the ratio 1 : 3 : 5. The ratio of the their
electrical resistance is :

(A) 5 : 3 : 1 (B) 125 15 1  (C) 1 : 15 : 125 (D) 1 : 3 : 5

7. Consider a thin square sheet of side L and thickness t, made of a
material of resistivity  . The resistance between two opposite faces,

shown by the shaded areas in the figure :
(A) directly proportional to L
(B) directly proportional to t
(C) independent of L
(D) independent of t

8. Two conductors have the same resistance at 0 C but their temperature coefficients of resistance are 1 2and  . The respective

temperature coefficients of their series and parallel combinations are nearly.

(A) 1 2 1 2
2

 
 


  (B) 1 21 2

2

 
 


  (C) 1 21 2

1 2

 
 

 
 


(D) 1 2 1 2

2 2

    


Page 2

Vidyamandir Classes

VMC/DC Circuits 74 HWT-6/Physics

9. A battery of emf E has an internal resistance r. A variable resistance R is connected to the terminals of the battery. a current i is
drawn from the battery. V is the terminal potential difference. If R along is gradually reduced to zero, which of the following best
describes i and V?

(A) i approaches zero, V, approaches E (B) i approaches
E

r
, V approaches zero

(C) i approaches
E

r
, V approaches E (D) i approaches

E

r
, V approaches E

10. The amount of charge Q passed in time t through a cross - section of a wire is 25 3 1Q t t   . The value of current at time 5t s
is :
(A) 4 A (B) 49 A (C) 53 A (D) None of the above

11. An aluminum (Al) rod with area of cross - section 6 24 10 m has a current of 5 a flowing through it. find the drift velocity of

electron in the rod. Density of 3 32 7 10Al . kgm  and atomic wt. = 27 u. Assume that each Al atom provides one electron.

(A) 4 18 6 10. ms  (B) 4 11 3 10. ms  (C) 2 12 8 10. ms  (D) 3 13 8 10. ms 

12. The resistance of a wire at 300 K is found to be 0 3Ω. . If the temperature coefficient of resistance of wire is 3 11 5 10. K  , the

temperature at which the resistance become 0 6Ω. is :
(A) 720 K (B) 345 K (C) 993 K (D) 690 K

13. Two different conductors have same resistance at 0 C . It is found that the resistance of the first conductor at 1t C is equal to the

resistance of the second conductor at 2t C . The ratio of the temperature coefficients of resistance of the conductors,
1

2




is :

(A) 1
2

t

t
(B) 2 1

2

t t

t


(C) 2 1

1

t t

t


(D) 2

1

t

t

14. If the free electron density be n I and relaxation time be  , the electrical conductivity of a conductor may be expressed as

(A)
e

ne

m


(B)

2

e

ne

m


(C)

2

e

ne

m
(D)

2
em e

n



15. With the rise of temperature of the resistivity of a semiconductor
(A) remains unchanged (B) increases
(C) decreases (D) first increases and then decreases

Page 9

Vidyamandir Classes

VMC/DC Circuits 81 HWT-6/Physics

DATE : TIME : 40 Minutes MARKS : [ ___ /15] TEST CODE : DC CR [5]

START TIME : END TIME : TIME TAKEN: PARENT’S SIGNATURE :

 This test contains a total of 15 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. In the circuit shown the value of I in ampere is :
(A) 1
(B) 0.60
(C) 0.4
(D) 1.5

2. The equivalent resistance between points A and B of an infinite

network of resistances, each of 1Ω , connected as shown is:

(A) infinite (B) 2Ω

(C)
1 5

Ω
2


(D) Zero

3. In circuit shown below, the resistances are given in ohm and the battery is
assumed ideal with emf equal to 3V. The voltage across the resistance R4 is :
(A) 0.4 V
(B) 0.6 V
(C) 1.2 V
(D) 1.5 V

4. In the given circuit the equivalent resistance between the points A
and B in ohm is :
(A) 9
(B) 11.6
(C) 14.5
(D) 21.2

5. In the given figure the steady state
current in the circuit is :
(A) zero
(B) 0.6 A
(C) 0.9 A
(D) 1.5 A

6. The resistance of the series combination of two resistances is S. When they are joined in parallel, the total resistance is P.
If S = nP, then the minimum possible value of n is :
(A) 4 (B) 3 (C) 2 (D) 1

7. Six equal resistances are connected between points P, Q and R as shown in
the figure. Then the net resistance will be maximum between :
(A) P and Q
(B) Q and R
(C) P and R
(D) Only two points

Page 10

Vidyamandir Classes

VMC/DC Circuits 82 HWT-6/Physics

8. In the circuit given E = 6.0 V, 100 ΩR  , 2 3 50ΩR R  , 4 75ΩR  .

The equivalent resistance of the circuit, in ohm, is :

(A) 11.875 (B) 26.31

(C) 118.75 (D) None of these

9. By using only two resistance coils - singly, in series or in parallel one should be able to obtain resistances of 3, 4, 12, and 16 ohm.
The separate resistances of the coil are :
(A) 3 and 4 (B) 4 and 12 (C) 12 and 16 (D) 16 and 3

10. n conducting wires of same dimensions but having resistivity's 1, 2, 3, ....... , n are connected in series. The equivalent resistivity of
the combination is

(A)
 1

2

n n
(B)

1

2

n 
(C)

2

2

n

n


(D)

2

1

n

n

11. Thirteen resistances each of resistance ΩR are connected
in the circuit as shown in the figure. The effective
resistance between points A and B is :

(A) Ω
3

R

(B) 2 ΩR

(C) ΩR

(D)
2

Ω
3

R

12. Two cells with the same emf E and different internal resistances 1 2andr r are connected in series to an external resistance R.

The value of R so that the potential difference across the first cell be zero is :

(A) 1 2r r (B) 1 2r r (C) 1 2r r (D)
1 2

2

r r

13. The maximum power dissipated in an external resistance R, When connected to a cell of emf E and internal resistance r, will be :

(A)
2E

r
(B)

2

2

E

r
(C)

2

3

E

r
(D)

2

4

E

r

14. In the circuit given here, the points A, B and C 70 V, zero, 10V respectively. Then :
(A) the point D will be at a potential of 60 V
(B) the point D will be at a potential of 20 V
(C) currents in the paths AD, BD and DC are in the ratio of 1 : 2 : 3
(D) currents in the paths AD, DB and DC are the ratio of 3 : 2 : 1

15. Two similar cells, whether joined in series or in parallel, have the same current through an external resistance of 2Ω . The internal
resistance of each cell is :

(A) 1Ω (B) 2Ω (C) 0 5Ω. (D) 1 5 Ω.

Page 17

Vidyamandir Classes

VMC/DC Circuits 89 HWT-6/Physics

DATE : TIME : 40 Minutes MARKS : [ ___ /15] TEST CODE : DC CR [6]

START TIME : END TIME : TIME TAKEN: PARENT’S SIGNATURE :

 This test contains a total of 15 Objective Type Questions. Each question carries 1 mark. There is NO NEGATIVE marking.

Choose the correct alternative. Only one choice is correct.

1. Potentiometer measures the potential difference more accurately than a voltmeter because
(A) it has a wire of high resistance (B) it has a wire of low resistance
(C) it does not draw current from external circuit (D) it draws a heavy current from external circuit

2. The length of a wire of a potentiometer is 100 cm, and the emf of its stand and cell is E volt. It is employed to measure the emf of a

battery whose internal resistance is 0 5Ω. . If the balance point is obtained at 30l  cm from the positive end, the emf of the

battery is:

(A)
30

100 5

E

.
(B)

30

100 0 5

E

.

(C)
 30 0 5

100

E . i
where i is the current in the potentiometer wire (D)

30

100

E

3. An unknown resistance R1 is connected in series with a resistance of 10Ω . This combination is connected to one gap of meter
bridge while a resistance R2 is connected in the other gap. The balance point is at 50 cm. Now, when the 10Ω resistance is

removed the balance point shifts to 40 cm. The value of R1 (in ohm) is :
(A) 20 (B) 10 (C) 60 (D) 40

4. For the post office box arrangement to determine the value of
unknown resistance, the unknown resistance, the unknown resistance
should be connected between

(A) B and C

(B) C and D

(C) A and D

(D) B1 and C1

5. The ratio of voltage sensitivity (VS) and current sensitivity (IS) of a moving coil galvanometer is :

(A)
1

G
(B)

2
1

G
(C) G (D) 2G

6. A galvanometer acting as a voltmeter should have
(A) low resistance in series with its coil (B) low resistance in parallel with its coil
(C) high resistance in series with its coil (D) high resistance in parallel with its coil

7. A galvanometer has a resistance of 3663Ω . A shunt S is connected across it such that (1/34) of the total current passes through the
galvanometer. Then the value of shunt is :
(A) 3663 Ω (B) 111Ω (C) 107 7 Ω. (D) 3555 3 Ω.

8. To decrease the range of an ammeter, its resistance need to be increased. An ammeter has resistance R0 and range I. Which of the
following resistance can be connected in series with it to decreases its range to I/n?

(A) 0
R

n
(B)

 
0

1

R

n 
(C)

 
0

1

R

n 
(D) None of these

Page 18

Vidyamandir Classes

VMC/DC Circuits 90 HWT-6/Physics

9. In the given circuit, the voltmeter records 5 V. The resistance of the voltmeter in ohm is:

(A) 200

(B) 100

(C) 10

(D) 50

10. A moving coil galvanometer of resistance 100Ω is used as an ammeter using a resistance 0 1Ω. . The maximum deflection current

in the galvanometer is 100 A . Find the minimum current in the circuit so that the ammeter shows maximum deflection.

(A) 100.1 mA (B) 1000.1 mA (C) 10.01 mA (D) 1.01 mA

11. A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milliampere and voltage sensitivity
is 2 divisions per millivolt. In order that each division reads 1 V, the resistance in Ohm's needed to be connected in series with the
coil will be :
(A) 103 (B) 105 (C) 99995 (D) 9995

12. If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a
(A) low resistance is parallel (B) high resistance in parallel
(C) high resistance in series (D) low resistance is series

13. A current of 0.01 mA passes through the potentiometer wire of a resistivity of 10Ω cm and area of cross - section 2 210 cm . The

potential gradient is :

(A) 9 110 Vm (B) 11 110 Vm (C) 10 110 Vm (D) 8 110 Vm

14. Three moving coil galvanometers A, B and C are made of coils of three different material having torsional constant
8 8 81 8 10 2 8 10 and 3 8 10. . .      respectively. If the three galvanometers are identical in all other respect, then in which of the

above cases sensitivity is maximum?
(A) A (B) C (C) B (D) Same in each case

15. The plates of a charged condenser are connected to a voltmeter. If the plates are moved apart, the reading of voltmeter will
(A) increase (B) decrease (C) remain unchanged (D) information is insufficient

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