MCQOPTIONS
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MCQOPTIONS
This section includes 80 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
In parallel connection the current flows through each resistor is? |
| A. | maximum |
| B. | same |
| C. | None of these |
| D. | different |
| Answer» E. | |
| 52. |
When resistors are connected in parallel the reciprocal of the equivalent resistance is equal to? |
| A. | the sum of individual resistances. |
| B. | product of the individual resistances |
| C. | the sum of the reciprocals of the individual resistances |
| D. | None of these |
| Answer» D. None of these | |
| 53. |
According to Ohm's law? |
| A. | V = 12R |
| B. | V = IR |
| C. | V = 1R2 |
| D. | V = I2R2 |
| Answer» C. V = 1R2 | |
| 54. |
Only for non-metallic resistance. |
| A. | Only for non-metallic resistance. |
| B. | None of these. |
| C. | only for metallic resistance at a given temperature and for steady currents |
| D. | only for steady currents. |
| Answer» D. only for steady currents. | |
| 55. |
The terminal potential difference of a battery becomes equal to its e.m.f when its internal resistance, is? |
| A. | maximum |
| B. | very low |
| C. | infinite |
| D. | zero |
| Answer» E. | |
| 56. |
A dry cell supplies? |
| A. | None of above |
| B. | Both alternating and direct current |
| C. | direct current |
| D. | alternating current |
| Answer» D. alternating current | |
| 57. |
The unit of resistivity is? |
| A. | Ohm |
| B. | Ohm—m3 |
| C. | Ohm-m2 |
| D. | Ohm—m |
| Answer» E. | |
| 58. |
When a temperature rises, the drift velocity of the free electrons decreases. Hence for given applied voltage? |
| A. | the electric current decreases, which increases the electrical resistance |
| B. | the electric current decreases, which increases the electrical resistance |
| C. | None of the above. |
| D. | only electric resistance decrease and current remain same |
| Answer» B. the electric current decreases, which increases the electrical resistance | |
| 59. |
Metal resistors that conduct in accordance with Ohm's law are said to be? |
| A. | Ohms component |
| B. | Ohmic |
| C. | Ohmmeter |
| D. | Omega |
| Answer» C. Ohmmeter | |
| 60. |
In parallel connection, the potential different across each resistors is? |
| A. | zero |
| B. | same |
| C. | different |
| D. | maximum |
| Answer» C. different | |
| 61. |
The internal resistance of a cell of emf 12 V is 5 x 10 -2 Ω . It is connected across an unknown resistance. Voltage across the cell, when a current of 60 A is drawn from it, is |
| A. | 15 V |
| B. | 12 V |
| C. | 6 V |
| D. | 15 V |
| Answer» E. | |
| 62. |
The resistance of an incandescent lamp is |
| A. | Greater when switched off |
| B. | The same whether it is switched off or switched on |
| C. | Smaller when switched on |
| D. | None of these |
| Answer» D. None of these | |
| 63. |
Read the following statements carefully Y: The resistivity of a semiconductor decreases with increase of temperature Z : In a conducting solid, rate of collisions between free electrons and ions increases with increases of temperature Select the correct statements (s) from the following |
| A. | Both Y and Z are true |
| B. | Y is false but Z is true |
| C. | Y is true and Z is the correct reason for Y |
| D. | Y is true but Z is false |
| Answer» B. Y is false but Z is true | |
| 64. |
A uniform wire of resistance R is uniformly compressed along its length, until its radius becomes n times the original radius. New resistance of the wire becomes |
| A. | nR |
| B. | R/n2 |
| C. | R/n4 |
| D. | R/n |
| Answer» D. R/n | |
| 65. |
A uniform resistance wire of length L and diameter d has a resistance R. Another wire of same material has length 4L and diameter 2d, the resistance will be |
| A. | R/2 |
| B. | 2R |
| C. | R |
| D. | R/4 |
| Answer» D. R/4 | |
| 66. |
Identify the set in which all the three materials are good conductor of electricity |
| A. | Cu, Ag, Au |
| B. | Cu, Ag, Au |
| C. | Cu, Si, Diamond |
| D. | Cu, Ge, Hg |
| Answer» B. Cu, Ag, Au | |
| 67. |
Two resistance r1 and r2 (r1 < r2 ) are connected in parallel. Their equivalent resistance R is |
| A. | r1 < R < ( r1 + r2) |
| B. | R < r1 |
| C. | r1 < R < r2 |
| D. | R < ( r1 > r2) |
| Answer» C. r1 < R < r2 | |
| 68. |
Three resistors are connected to form the sides of a triangle ABC, the resistance of the sides AB, BC and CA are 40 ohms; 60 ohms and 100 ohms respectively. The effective resistance between the points A and B in ohms will be |
| A. | 64 |
| B. | 200 |
| C. | 50 |
| D. | 32 |
| Answer» E. | |
| 69. |
A wire of 50 cm long and 1 mm2 in cross-sectional area carries a current 4A when connected to a 2V battery. The resistivity of the wire is |
| A. | 4 x 10-6 Ωm |
| B. | 2 x 10-7 Ωm |
| C. | 5 x 10-7 Ωm |
| D. | 1 x 10-6 Ωm |
| Answer» E. | |
| 70. |
Which of the following does not obey Ohm's law |
| A. | Diode-valve |
| B. | Copper |
| C. | Aluminium |
| D. | None of these |
| Answer» B. Copper | |
| 71. |
Resistance of a wire is r ohms. The wire is stretched to double its length, then its resistance in ohms is |
| A. | 4 r |
| B. | 2 r |
| C. | r / 2 |
| D. | r / 4. |
| Answer» B. 2 r | |
| 72. |
Two bulbs marked 200 watt-250 volts and 100 watt-250 volts are joined in series to 250 volts supply. Power consumed in circuit is |
| A. | 33 watt |
| B. | 100 watt |
| C. | 67 watt |
| D. | 300 watt. |
| Answer» D. 300 watt. | |
| 73. |
Superposition theorem is not applicable for |
| A. | voltage calculation |
| B. | bilateral elements |
| C. | passive elements |
| D. | power calculations |
| Answer» E. | |
| 74. |
The charge on an electron is known to be 1.6 x 10-19 coulomb. In a circuit the current flowing is 1 A. How many electrons will be flowing through the circuit in a second? |
| A. | 0.625 x 1019 |
| B. | 1.6 x 10-19 |
| C. | 1.6 x 1019 |
| D. | 0.625 x 1012. |
| Answer» B. 1.6 x 10-19 | |
| 75. |
Which of the following theorem is applicable for both linear and non-linear circuits ? |
| A. | None of these |
| B. | Norton theorem |
| C. | Superposition theorem |
| D. | Thevenin theorem |
| Answer» B. Norton theorem | |
| 76. |
The value of the following is given by 100 (kilo ampere ) x ( micro ampere ) 100 milli ampere * 10 ampere |
| A. | 0.001 A |
| B. | 0.1 A |
| C. | 10A. |
| D. | 0.041666667 |
| Answer» C. 10A. | |
| 77. |
A cell of internal resistance 3 ohm and emf 1 volt is connected to a uniform wire of length 500 em and resistance 3 ohm. The potential gradient in the wire is |
| A. | 30 mV/cm |
| B. | 1 mV/cm |
| C. | 4 mV/cm |
| D. | 20 mV/cm |
| Answer» C. 4 mV/cm | |
| 78. |
The resistance of a coil is 4.2 Ω at 100°C and the temperature coefficient of resistance of its material is 0.004 °C. Its resistance at Q °C is |
| A. | 5Ω |
| B. | 6.5 C |
| C. | 3Ω |
| D. | 4Ω |
| Answer» D. 4Ω | |
| 79. |
A circuit contains two un-equal resistances in parallel |
| A. | potential difference across each is same |
| B. | smaller resistance has smaller conductance. |
| C. | large current flows in larger resistor |
| D. | current is same in both |
| Answer» B. smaller resistance has smaller conductance. | |
| 80. |
The resistors of resistances 2 Ω, 4 Ω and 8 Ω are connected in parallel, then the equivalent resistance of the combination will be |
| A. | 7/4 Ω |
| B. | 8/7 Ω |
| C. | 7/8 Ω |
| D. | 4/9 Ω |
| Answer» C. 7/8 Ω | |