# General Science - Physics MCQs

Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examinations.

81. Which of the following part of eyes controls the size of the pupil?

[A] Retina
[B] iris
[C] Cornea
[D] None of the above

82. As per Ohm’s law, if the resistance of a conductor is doubled, what will be the effect on the current flowing through it?

[A] it gets doubled
[B] it gets halved
[C] it increases 4 times
[D] No change

83. What is the equivalent internal resistance of a series combination of n cells?

[A] the arithmetic mean of their internal resistance
[B] the product of their individual internal resistance
[C] the sum of their individual internal resistance
[D] the sum of the reciprocal of their individual internal resistance

84. What is the device used to measure the cell potential?

[A] Ammeter
[B] Voltmeter
[C] Wattmeter
[D] None of the above

85. Which of these is NOT a product of a fuel cell?

[A] Water
[B] Electricity
[C] Heat
[D] None of the above

86. What is the direction of current through electrolyte in a galvanic cell?

[A] flows from cathode to anode
[B] flows from anode to cathode
[C] flows in both direction
[D] None of the above

87. What is the direction of current through external circuit in a galvanic cell?

[A] flows from cathode to anode
[B] flows from anode to cathode
[C] flows in both direction
[D] None of the above

88. Which of the following is correct about an electric motor?

[A] It converts potential energy to chemical energy
[B] It converts electrical energy to mechanical energy
[C] It converts mechanical energy to electrical energy
[D] None of the above

89. Which of these is used to accelerate charged particles or ions to high energies?

[A] Solenoid
[B] Cyclotron
[C] Electric motor
[D] Toroid