Q.1
In the circuit, each cell has an emf of 1.5 V and r=0.4Ω. The current I in the 36Ω resistor is
ch-14_que_no-303_img_no1.png
  • a) 0.5 amp
  • b) 0.1 amp
  • c)0.083 amp
  • d)0.2 amp
Q.2
A galvanometer together with unknown resistance in series is connected to two identical batteries each of 1.5 V. When the batteries are connected in series the galvanometer registers a current of 1 ampere. When the batteries are in parallel the current is 0.6 ampere. The internal resistance of battery is
  • a) 3 Ω
  • b) 2 Ω
  • c) (1/3) Ω
  • d) (1/2) Ω
Q.3
Two cells with emf ε1=1.3 V and ε2=1.5 V are connected as shown. The voltmeter reads 1.15V. If r1 and r2 be the internal resistance of the cells, the ratio r1 / r2 is
ch-14_que_no-305_img_no1.png
  • a)2/5
  • b) 3/1
  • c)4/3
  • d)3/2
Q.4
Each resistance in the circuit is r. The equivalent resistance between A and B is
ch-14_que_no-306_img_no1.png
  • a) r/4
  • b) 4r
  • c)2r/5
  • d)0
Q.5
An ammeter and voltmeter are joined in series to a cell. There readings are A and V respectively. If a resistance is now joined in parallel with voltmeter.
  • a) both A and V will increase
  • b) both A and V will decrease
  • c)A will decrease, V will increase
  • d)A will increase, V will decrease
Q.6
The equivalent resistance between A and B is
ch-14_que_no-308_img_no1.png
  • a) 2R/3
  • b) R/3
  • c) R
  • d) 3R
Q.7
In a circuit shown, the galvanometer reads zero. If batteries have negligible internal resistance, the value of C will be
ch-14_que_no-309_img_no1.png
  • a)10 Ω
  • b) 100 Ω
  • c)200 Ω
  • d)500 Ω
Q.8
The reading in the ammeter is
ch-14_que_no-310_img_no1.png
  • a) 1 A
  • b) 2 A
  • c)0.67 A
  • d)1.5 A
Q.9
The potential difference between the points x and y in the adjoining figure will be
ch-14_que_no-311_img_no1.png
  • a)zero
  • b) 50 V
  • c)10 V
  • d)100V
Q.10
In the adjoining diagram find the current through 10Ω resistance
ch-14_que_no-312_img_no1.png
  • a) 0.4 A towards O
  • b) 0.4 A away from O
  • c) 0.6 A towards O
  • d) 0.6 A away from O
Q.11
In the circuit given below. The current in the arm AD will be , each resistance is 10Ω
ch-14_que_no-313_img_no1.png
  • a)2i/5
  • b) 3i/5
  • c)4i/5
  • d)i/5
Q.12
A steady current is passing through a linear conductor of non-uniform cross-section. the current density in the conductor is
  • a) independent of area of cross section
  • b) directly proportional to area of cross section
  • c)inversely proportional to area of cross-section
  • d)inversely proportional to the square root of area of cess-section
Q.13
A metallic block has no potential difference applied across it. Then the mean velocity of free electron in a conductor at absolute temperature T is
  • a) proportional to T
  • b) proportional to √T
  • c)zero
  • d)finite but independent of temperature
Q.14
Ohm's law is valid when the temperature of the conductor is
  • a) constant
  • b) very high
  • c) very low
  • d) varying
Q.15
Two wires of the metal have the same length but their cross-sections are in the ratio 3:1 They are joinedin series: The resistance of the thicker wire is 10Ω . The total resistance of the combination will be
  • a)40
  • b) 40/3
  • c)5/2
  • d)100
Q.16
A potentiometer wire has length 10 m and resistance 20 Ω. A 2.5V battery of negligible internal resistanceis connected across the wire with an 80Ω series resistance. The potential gradient on the wire will be:
  • a) 2.5 × 10 ×10-4 V/m
  • b) 0.62 × 10 ×10-4 V/mm
  • c)1 × 10-5 V/mm
  • d)5 × 10-5 V/mm
Q.17
Two heater wires of equal length are first connected in series and then in parallel The ratio of heatproduced in the two cases is....
  • a) 2:1
  • b) 1:2
  • c) 4:1
  • d) 1:4
Q.18
2 A current is obtained when a 2 Ω resistor is connected with battery having r Ω as internal resistance0.5A current is obtained if the above battery is connected to 9Ω resistor. Calculate the internal resistanceof the battery.
  • a) 0.5 Ω
  • b) (1/3) Ω
  • c) (1/4) Ω
  • d) 1 Ω
Q.19
A wire of resistance 4 Ω is stretched to twice itsoriginal length. The resistance of stretched wirewould be
  • a) 2 Ω
  • b) 4 Ω
  • c) 8 Ω
  • d) 16Ω
Q.20
The internal resistance of a 2.1 V cell which gives acurrent of 0.2 A through a resistance of 10 Omega; is
  • a) 0.2 Ω
  • b) 0.5 Ω
  • c) 0.8 Ω
  • d) 1.0 Ω
Q.21
The resistances of the four arms P, Q, R and S in a Wheatstone's bridge are 10 ohm, 30 ohm, 30 ohm and 90 ohm, respectively. The e.m.f. and internal resistance of the cell are 7 volt and 5 ohm respectively. If the galvanometer resistance is 50 ohm, the current drawn from the cell will be from the cell will be
  • a) 1.0 A
  • b) 0.2 A
  • c) 0.1 A
  • d) 2.0A
Q.22
In an ammeter 0.2% of main current passes through the galvanometer. If resistance of galvanometer is G, the resistance of ammeter will be
  • a) G/500
  • b) 500G/499
  • c) G/499
  • d) 499G/500
Q.23
The resistance in the two arms of the meter-bridge are 5Ω and RΩ, respectively.When the resistance R is shunted with an equal resistance,the new balance point is at 1.6l1.The resistance 'R', is
ch-14_que_no-325_img_no1.png
  • a) 20 Ω
  • b) 25Ω
  • c) 10Ω
  • d) 15Ω
Q.24
Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is 8 volt and the average resistance per km is0.5 立. The power loss in the wire is Answer : (d)
  • a) 19.2J
  • b) 12.2 kW
  • c) 19.2W
  • d) 19.2 kW
Q.25
A potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0 V and a negligible internal resistance. The potentiometer wire itself is 4m long.When the resistance R, connected across the given cell, has values of(i)infinity(ii) 9.5Ω, the 'balancing lengths', on the potentiometer wire are found to be 3m and 2.85 m, respectively. The value of internal resistance of the cell is
  • a) 0.5Ω
  • b) 0.75Ω
  • c) 0.25Ω
  • d) 0.95Ω
Q.26
A, B and C are voltmeters of resistance R, 1.5 R and 3R respectively as shown in the figure. When some potential difference is applied between X and Y, the voltmeter readings are VA, VB and VC respectively. Then :
ch-14_que_no-328_img_no1.png
  • a) VA ≠ VB ≠ VC
  • b) VA = VB = VC
  • c) VA ≠ VB = VC
  • d) VA = VB ≠ VC
Q.27
A potentiometer wire has length 4 m and resistance 8 Ω. The resistance that must be connected in series with the wire and an accumulator of e.m.f. 2V, so as to get a potential gradient 1 mV per cm on the wire is :
  • a) 48 Ω
  • b) 32 Ω
  • c) 40 Ω
  • d) 44 Ω
Q.28
s a metallic conductor of non-uniform cross section a constant potential difference is applied. The quantity which remains constant along the conductor is :
  • a) electric filed
  • b) current density
  • c) current
  • d) drift velocity
Q.29
A potentiometer wire of length L and a resistance are connected in series with a battery of e.m.f. E0 and a resistance rAn unknown e.m.f. E is balanced at a length l of the potentiometer wire. The e.m.f. E will be given by :
  • a)
    ch-14_qn-331choice_img_no1.png
  • b)
    ch-14_qn-331choice_img_no2.png
  • c)
    ch-14_qn-331choice_img_no3.png
  • d)
    ch-14_qn-331choice_img_no4.png
Q.30
Two metal wires of identical dimensions are connected in series. If σ1 and σ2 are the conductivities of the metal wires respectively, the effective conductivity of the combination is :-
  • a)
    ch-14_qn-332choice_img_no1.png
  • b)
    ch-14_qn-332choice_img_no2.png
  • c)
    ch-14_qn-332choice_img_no3.png
  • d)
    ch-14_qn-332choice_img_no4.png
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