All Free Physics MCQs with Answers

• A. Low resistance in comparison to circuit resistance
• B. High resistance in comparison to circuit resistance
• C. A resistance equal to circuit resistance
• D. None of the above

Explanation: High resistance in comparison to circuit resistance: This is the correct option.

• A. Resistance
• B. Conductance
• C. Temperature coefficient of resistivity
• D. Conductivity

Explanation: When two metals have the same resistance, they can be differentiated based on their conductivity.

• A. the same
• B. one fourth
• C. double
• D. one half

Explanation: Resistivity remains constant, it is a constant value.

• A. 3R
• B. R/3
• C. R
• D. 2R

Explanation: When three equivalent resistors are connected in parallel, the equivalent resistance is 3/R.

• A. Semiconductors
• B. Tungsten filament
• C. Thermistor
• D. Metals

Explanation: Ohmic materials are those that follow Ohm's Law, where the resistance (R) is constant regardless of the applied voltage (V) or current…

• A. 2R
• B. 4R
• C. 8R
• D. 16R

Explanation: To determine the new resistance, use the formula Resistance = resistivity × length/area.

• A. Copper
• B. Thermistor
• C. Soft iron
• D. Platinum

Explanation: NTC, negative thermistors are resistors with a negative temperature coefficient which means the resistance decreases with increasing…

• A. 50 W
• B. 750 W
• C. 500 W
• D. 1000 W

Explanation: To find the power dissipated in the cables, you need to first calculate the current flowing through the circuit.

• A. Thermistor
• B. Bulb filament
• C. Metals
• D. Semiconductors

Explanation: Ohm's law is valid for metallic conductors because they have a linear relationship between current and voltage.

• A. Increase
• B. Decrease
• C. Not change
• D. None of these

Explanation: In a parallel circuit, the net resistance decreases as more components are added, because there are more paths for the current to pass…

• A. 2.5 times
• B. 5 times
• C. 10 times
• D. 30 times

Explanation: The Resistance of a wire is calculated asR = P L/Awhere R = resitance of the wireL = Length of the wireA is the area of the wire = (pi…

• A. 0.25 A
• B. 1.0 A
• C. 4.0 A
• D. 5.0 A

Explanation: Parallel Resistance is calculated by 1/Rt= (1/R1 + 1/R2 ...) hence Rt = 5Ohm. EMF is 20, and Ohm's Law, V=IR, determines I (current) as 4.0A

• A. Only the current is doubled
• B. Only the current is halved
• C. Only the resistance is doubled
• D. Only the resistance is halved

Explanation: The correct answer is that only the current is doubled. According to Ohm's law (V = IR), the current through a resistor is directly…

• A. r/2
• B. 4r
• C. 2r
• D. r/4

Explanation: When a wire is stretched to double its length, its resistance R changes according to the formula: [R' = 2R] So, the resistance of the wire…

• A. √GM/Re
• B. √GMe/Re
• C. √GMe/R²
• D. √GMe/h

Explanation: The correct formula to calculate the orbital speed (v) of a satellite orbiting the Earth is: v = √(GMe/r) where G is the gravitational…

• A. 1 hour
• B. 2 hour
• C. 12 hours
• D. 24 hours

Explanation: 24 hours: This option is correct. Geostationary communication satellites orbit the Earth at a height of about 35,786 kilometers, taking 24…

• A. rotation of earth
• B. mass of body
• C. radius of earth
• D. mass of earth

Explanation: Escape velocity, Ve =√( 2GM/R) Acceleration due to gravity, g= GM/R², which is always constant.

• A. stationary
• B. Rotating with the speed of earth
• C. rotating very fastly
• D. rotating very slowly

Explanation: Geostationary satellites remain at the same position with respect to the Earth, so that they scan the same place in a better way.

• A. V ∞ r2
• B. V ∞ r
• C. V1 ∞ 1/r
• D. V ∞ 1/r2

Explanation: d) V ∞ 1/r^2 (V is proportional to 1/r^2):This option correctly represents the relationship between the speed (V) of a satellite and the…

• A. √2gR
• B. √Rg
• C. Rg/2
• D. Rg

Explanation: The force on a mass m, having an angular velocity ω orbiting in a circular path of radius R is F=mRω2.