Q.1
Increase in which property of free electrons causes increase in the resistance of a conductor with rise in temperature?
  • a)number density
  • b) relaxation times
  • c)mass
  • d)none of above
Q.2
A steady current is set up in a metallic wire of non-uniform cross-section. How is the rate flow of electrons (R) related to the area of cross-section A?
  • a) R is independent of A
  • b) R ∝ A-1
  • c)R ∝ A
  • d)R ∝ A2
Q.3
Two unequal resistor are connected in series with a cell. Which of the following statement is true?
  • a) Potential drop across either resistor is same
  • b) Potential drop across smaller resistor is more
  • c)Potential drop across larger resistor is more
  • d)Any one of the above can be true depends on the emf of the cell
Q.4
A potential difference of 10V is applied across a conductance 4 S. The current in the conductor is
  • a) 40 A
  • b) 2.5 A
  • c) 2.4 A
  • d) none of the above
Q.5
The resistivity of a material is inversely proportional to
  • a)number density of electrons as well as relaxation time
  • b) number density of electrons and directly proportional to relaxation time
  • c)relaxation time and directly proportional to the number density of electrons
  • d)neither relaxation time nor number density of electrons
Q.6
How will the reading in ammeter A affected if another identical bulb Q is connected in parallel to P as shown in figure . The voltage of the mains is maintained at a constant value
ch-14_que_no-234_img_no1.png
  • a) the reading will be reduced to one half
  • b) the reading will not affected
  • c)the reading will be double of previous one
  • d)the reading will be increased to four fold
Q.7
Wire of resistance 0.5 Ω/m is bent into a circle of radius 1 m. The same wire is connected across a diameter AB as shown in figure. The equivalent resistance is
ch-14_que_no-235_img_no1.png
  • a)π ohm
  • b)π/ (π+2) ohm
  • c)π/ (π+ 4) ohm
  • d)(π+1) ohm
Q.8
A galvanometer together with an unknown resistance in series is connected across two identical cells each of 1.5V. When the batteries are connected in series, the galvanometer records a current of 1A and when the batteries are connected in parallel, the current is 0.6A. The internal resistance of the battery is
  • a) 0.33 Ω
  • b) 1 Ω
  • c) 0.66Ω
  • d) 0.5Ω
Q.9
In figure point x and y represent the terminals of an unknown emf. On moving jockey J from A towards B it is observed that deflection of galvanometer remains in the same direction but increases. Which one of the following conclusions is correct
ch-14_que_no-237_img_no1.png
  • a)the emf E is less than the unknown emf
  • b) the emf E is more than the unknown emf
  • c)the potential drop of potential across potentiometer wire is less than the unknown emf
  • d)the unknown emf is wrongly connected
Q.10
In figure the potentiometer wire AB has a resistance of 5Ω and length 10 m. The balancing length AJ for the emf of 0.4V is
ch-14_que_no-238_img_no1.png
  • a) 8 m
  • b) 0.8 m
  • c)4 m
  • d)0.4 m
Q.11
Circuit whose resistance is R is connected to n similar cells. If the current in the circuit is the same whether the cells are connected in series or in parallel, then the internal resistance r of each cell is given by
  • a) r=R/n
  • b) r=nR
  • c)r=R
  • d)r=1/R
Q.12
In the following figure, the reading of an ideal voltmeter V is zero. Then the relation between R, r1 and r2 is
ch-14_que_no-240_img_no1.png
  • a) r=r₂ - r₁
  • b) R=r₁ - r₂
  • c) R=r₁ + r₂
  • d) R=r1r2 / (r₁ + r₂ )
Q.13
A primary cell has emf 2 volts. When short circuited, it gives current of 4 amp. Its internal resistance in ohms will be
  • a)0.5
  • b) 2
  • c)5
  • d)8
Q.14
A cell of e.m.f E volts and internal resistance r ohm is supplying a current of i ampere to external circuit, then the terminal potential difference is
  • a) E
  • b) E - ir
  • c)E + ir
  • d)E ± ir
Q.15
In the following figure, the value of resistor to be connected between C and D so that the resistance of the entire circuit between A and B does not change with the number of elementary sets used is( each resistance in circuit is of value R :
ch-14_que_no-243_img_no1.png
  • a)R
  • b) R(√3 -1)
  • c)3R
  • d)R(√3 + 1)
Q.16
Twelve equal resistors, each of resistance r, are connected to form a skeleton cube. Then the equivalent resistance taken between tow diagonally opposite corners is
  • a) r
  • b) 12r
  • c)5r/6
  • d)(7/12)r
Q.17
In the above question, the equivalent resistance between the adjacent corners of any one face of the cube is
  • a) r
  • b) 12r
  • c)5r/6
  • d)(7/12)r
Q.18
In the following figure the resistance of galvanometer G is 50Ω. Of the following alternatives in which case are the currents arranged strictly in the order of decreasing magnitudes with the larger coming earlier
ch-14_que_no-248_img_no1.png
  • a) i, i2, ig, i1
  • b) i , ig, i1, i2
  • c) i, i2, i1, ig
  • d) ig, i1, i2, i
Q.19
In Wheatstone's bridge, P=9 ohms, Q=11 ohms, R=4 ohms and S=6 ohms. How much resistance must be put in parallel to the resistance S to balance bridge?
  • a)24 ohms
  • b) (44/9) ohms
  • c)26.4 ohms
  • d)18.7 ohms
Q.20
In figure to make the bulb of rating 5W, 2V glow at normal intensity, the emf E is its internal resistance is 0.46Ω
ch-14_que_no-250_img_no1.png
  • a) 2 V
  • b) 2.76 V
  • c)3.75 V
  • d)5 V
Q.21
A battery of emf having internal resistance 1Ω is connected to a external resistor of resistance 4Ω . the rate of energy dissipation in battery is
  • a) 2W
  • b) 4W
  • c)6W
  • d)8W
Q.22
A current of 2A flows in a system of conductors as shown in the following figure. The potential difference VA - VB will be ( in volts)
ch-14_que_no-252_img_no1.png
  • a) +2
  • b) +1
  • c) -1
  • d) -2
Q.23
When a current is divided between two resistors according to Kirchhoff's law, then the heat produced is
  • a)zero
  • b) negligible
  • c)minimum
  • d)maximum
Q.24
An electric cell is
  • a) a source of charge
  • b) a source of energy
  • c)an energy converter
  • d)both a source of charge and of energy
Q.25
10 cells each of emf 1V and internal resistance 0.1Ω are to send maximum current through an external resistance of 100Ω, the cell be connected in
  • a) series
  • b) parallel
  • c)mixed grouping
  • d)can not say
Q.26
The potential difference V across a filament lamp is related to the current I by V=2I + 8IThe lamp is connected in one arm of a wheatstone bridge and a resistance of 4Ω each is connected in other arms. The potential difference that must be applied to the bridge, to obtain balance is
  • a) 1 V
  • b) 2 V
  • c) 4 V
  • d) 8 V
Q.27
To get maximum current in a resistance of 3Ω, one can use n rows connected in parallel. Each row contains m cells connected in series. If the total number of cells is 24 and the internal resistance of the cell is 0.5Ω, then
  • a) m = 12, n = 2
  • b) m = 8, n=3
  • c) m = 2, n = 12
  • d) m = 6, n =4
Q.28
A star ( as shown in figure) is made of uniform wire. The resistance of the arm EL is r ohm. The resistance of the star between the terminals C and F is
ch-14_que_no-258_img_no1.png
  • a) 1.946r
  • b) 0.937r
  • c) 0.62r
  • d) 3.892r
Q.29
Five identical resistance each of 1100Ω are connected to 220 volt as shown in the following figure. The reading of an ideal ammeter A is
ch-14_que_no-259_img_no1.png
  • a) 1 A
  • b) (3/5) A
  • c) (1/5) A
  • d) (2/5) A
Q.30
In figure the current through resistor R is
ch-14_que_no-260_img_no1.png
  • a) 3.0 A
  • b) 13.0 A
  • c) 6.5 A
  • d) 9.0 A
0 h : 0 m : 1 s