All Free Physics MCQs with Answers
Every Physics question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,934 questions · page 694 of 697
- A. Specific heat
- B. Molar specific heat
- C. Heat capacity
- D. Heat of vaporization
Explanation: The amount of heat energy required to raise the temperature of a body through 1 K (or 1 °C) is called:Heat capacity
Correct answer: Heat capacity- A. 775.00 K
- B. 774.85 K
- C. 228.85 K
- D. 228.70 K
Explanation: To convert from Celsius (C) to thermodynamic temperature, also known as Kelvin (K), you can use the formula:Kelvin (K) = Celsius (C) +…
Correct answer: 775.00 K13863. The statement that heat cannot spontaneously flow from a colder to a hotter body is a result of:
- A. Henry's law
- B. The first law of thermodynamics
- C. The second law of thermodynamics
- D. The third law of thermodynamics
Explanation: 2nd law of thermodynamics expresses a fundamental and simple truth about the universe, it states that heat cannot flow from colder body to…
Correct answer: The second law of thermodynamics- A. 775.00 K
- B. 774.85 K
- C. 228.85 K
- D. 228.70 K
Explanation: Thermodynamic temperature, by contrast, is an absolute measure of the average total internal energy of an object or objects-namely its…
Correct answer: 775.00 K- A. Transformer
- B. Generator
- C. Galvanometer
- D. Avometer
Explanation: A transformer is the most common application of mutual induction that uses this phenomenon to change the values of alternating voltages…
Correct answer: Transformer- A. Increase of power
- B. Increase of current
- C. Increase of voltage
- D. Increase of energy
Explanation: A step-up transformer is a type of transformer that increases the voltage of an alternating current (AC) while decreasing the current.
Correct answer: Increase of voltage- A. Area of cross section
- B. Length of solenoid
- C. Number of turns
- D. All of above
Explanation: Therefore, the correct option is "All of the above" as the inductance of a solenoid depends on the area of cross section, the length of…
Correct answer: All of above- A. 40
- B. 20
- C. 30
- D. 4
Explanation: 4: If there are 4 turns in the primary coil, the voltage transformation ratio would be 6000/4 = 1500, which matches the given…
Correct answer: 4- A. Energy
- B. AC voltage
- C. DC voltage
- D. Power
Explanation: An ideal transformer steps up or steps down AC voltage using the principle of electromagnetic induction.
Correct answer: AC voltage- A. Increase the power
- B. Increase the voltage
- C. Increase the energy
Explanation: A step-up transformer is a transformer that increases the voltage from the primary coil to the secondary coil.
Correct answer: Increase the voltage13871. The efficiency of a transformer which draws a power of 20 watt is 60%, the power supplied by it is:
- A. 5 W
- B. 1.2 W
- C. 6 W
- D. 12 W
Explanation: The formula for efficiency is:% Efficiency = (Total Power Output/Total Power Input) x 100So if power input is 20 W, and % Efficiency is…
Correct answer: 12 W- A. 16mA
- B. 2mA
- C. 8mA
- D. 4mA
Explanation: When a transformer steps down the voltage, it increases the current. In this case, since the voltage is stepped down from 220V to 55V, and…
Correct answer: 16mA13873. A step down transformer:
- A. Increases the output current
- B. Increases the output power
- C. Increases the output voltage
- D. Decreases the output power
Explanation: Actually, a step-down transformer decreases the output current while increasing the output voltage.
Correct answer: Increases the output voltage- A. 0
- B. 1
- C. -1
- D. 2
Explanation: The given expression i.(j×k) is an example of a scalar triple product, which represents the volume of the parallelepiped formed by the…
Correct answer: 113875. The direction of torque is:
- A. Parallel to the plane of F and γ
- B. Perpendicular to the plane of F and γ
- C. Anti parallel to the plane of F and γ
- D. Is the same as that of the plane of F and γ
Explanation: Perpendicular to the plane of F and γ: This option is correct as torque is always perpendicular to the plane defined by the force vector…
Correct answer: Perpendicular to the plane of F and γ13876. Axis equal to:
- A. 4
- B. Zero
- C. 2
- D. 1
Explanation: From the given diagram: i x j= k j x k= i k x i= j j x i = -k k x j= -i i x k= -j Now to solve the given expression, k x j= -i so j x -i =…
Correct answer: Zero- A. 0
- B. 1
- C. AB
- D. -AB
Explanation: If the dot product of two nonzero vectors (A) and (B) is zero, it means that they are orthogonal (perpendicular) to each other.
Correct answer: AB- A. Remains constant
- B. Becomes Half
- C. Becomes double
- D. Becomes four times
Explanation: As v=sqrt(T/d),Where T is tension and d is linear density of the stringAlso,d=m/l(mass per unit length)And mass is directly proportional…
Correct answer: Becomes Half- A. Remains constant
- B. Becomes half
- C. Becomes double
- D. Becomes four times
Explanation: The speed of transverse waves on a string is given by the formula v = √(T/μ), where T is the tension and μ is the linear density (mass per…
Correct answer: Becomes half- A. λ = v/f
- B. λ = vf
- C. λ = f/v
- D. None of above
Explanation: speed = frequency x wavelength Rearrange the formula and you get: wavelength = speed / frequency
Correct answer: λ = v/f