TG EAMCET Physics MCQs (91-100)

91. What is the relationship between electric current (I), voltage (V), and resistance (R) as given by Ohm’s law?

• a) I = V/R
• b) V = IR
• c) R = VI
• d) I = VR

Answer: b) V = IR

92. Which of the following materials has the highest resistivity?

• a) Copper
• b) Aluminium
• c) Tungsten
• d) Rubber

Answer: d) Rubber

93. What is the unit of resistivity?

• a) Ohm
• b) Ohm meter
• c) Siemens
• d) Watt

Answer: b) Ohm meter

94. The resistance of a conductor depends on:

• a) Length and temperature
• b) Temperature and cross-sectional area
• c) Length, cross-sectional area, and material
• d) Voltage applied

Answer: c) Length, cross-sectional area, and material

95. In a series combination of resistors, the total resistance is:

• a) Equal to the sum of individual resistances
• b) Equal to the reciprocal of the sum of the reciprocals of individual resistances
• c) Equal to the sum of the squares of individual resistances
• d) None of the above

Answer: a) Equal to the sum of individual resistances

96. Kirchhoff’s first law is based on the principle of:

• a) Conservation of charge
• b) Conservation of energy
• c) Conservation of momentum
• d) Conservation of power

Answer: a) Conservation of charge

97. A potentiometer is used to measure:

• a) Voltage
• b) Current
• c) Resistance
• d) Power

Answer: a) Voltage

98. The magnetic force on a current-carrying conductor is maximum when:

• a) The magnetic field is perpendicular to the current
• b) The magnetic field is parallel to the current
• c) The angle between the current and magnetic field is 45°
• d) The current is zero

Answer: a) The magnetic field is perpendicular to the current

99. In a cyclotron, charged particles move in a circular path due to:

• a) Electric field
• b) Magnetic field
• c) Gravitational force
• d) Electrostatic force

Answer: b) Magnetic field

100. The magnetic field at the center of a circular current loop is given by:

• a) μ₀ I / (2r)
• b) μ₀ I / (4r)
• c) μ₀ I / r
• d) μ₀ I / (πr)

Answer: a) μ₀ I / (2r)