Q.1
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.2
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.3
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.4
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.5
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.6
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.7
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.8
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.9
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.10
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.11
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.12
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.13
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.14
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.15
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.16
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.17
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.18
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.19
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
Q.20
A cell of e.m.f E and internal resistance r has an external resistance R connected across it. IF the terminal potential difference across the terminals of the cell is V, then
  • a)r=R
  • b) r=R(E/V)
  • c)r=R(E-V)/V
  • d)r=RV/E
Q.21
A capacitor of 10µF ha a potential difference of 40 V across it. If it is discharged in 0.2s, the average current during discharge is
  • a) 2 mA
  • b) 4 mA
  • c)1 mA
  • d)0.5 mA
Q.22
An external resistance R is connected to a cell of emf E and internal resistance r. Maximum power delivered to R is
  • a) E2 / r
  • b) E2 / 2r
  • c) E2 / 4r
  • d) E2 / 8r
Q.23
An external resistance R is connected to a cell of emf E and internal resistance r., the terminal potential difference is zero, when
  • a) R > r
  • b) R=r
  • c) R=0
  • d) R=∞
Q.24
The resistance of the circuit between A and B is ( each resistance is o r
ch-14_que_no-265_img_no1.png
  • a)r
  • b) 0.5r
  • c)2r
  • d)3r
Q.25
A battery of 20 cells is charged by 220V with a charging current of 15 ampere. If the e.m.f of each cell is 2 V and internal resistance is 0.1 Ω, then the series resistance required to be placed in the circuit is
  • a) 12 Ω
  • b) 14 Ω
  • c)10 Ω
  • d)16 Ω
Q.26
In above problem amount of power wasted as heat is
  • a) 450 watt
  • b) 3300 watts
  • c)2700 watt
  • d)2250 watt
Q.27
The resistance of the circuit between the points A and B is
ch-14_que_no-268_img_no1.png
  • a) R
  • b) 8R/3
  • c) 4R/3
  • d) cannot be calculated
Q.28
The length of a potentiometer wire required to balance the e.m.f of cell A is 60 cm. The length of the wire under the same conditions required to balance the e.m.f. if cll B is 45 Cm. If the e.m.f. of the cell B is 3.0 V, the e.m.f. of the cell A is
  • a)2.25 V
  • b) 2.5 V
  • c)4.0 V
  • d)4.5 V
Q.29
Five cells, each of e.m.f E and internal resistance r are connected in series. If due to oversight, one cell is connected wrongly, then the equivalent e.m.f. and internal resistance of combination is
  • a) 5E and 5r
  • b) 3E and 3r
  • c)3E and 5r
  • d)5E and 3r
Q.30
In figure , AB is a potentiometer wire of length 10m and resistance 2Ω. With key k open the balancing length is 5.5 m. However on closing key k the balancing length reduces to 5 m. The internal resistance of the cell E1 is :
ch-14_que_no-271_img_no1.png
  • a)0.01 Ω
  • b) 0.1 Ω
  • c)0.2 Ω
  • d)1.0Ω
0 h : 0 m : 1 s