CBSE Important Questions for Class 11 Physics - 2025-26

1.  What is the difference between scalar and vector quantities?

Answer: Scalar quantities have only magnitude (e.g., mass, temperature), while vector quantities have both magnitude and direction (e.g., velocity, force).

2.  State Newton's First Law of Motion.

Answer: Newton's First Law states that an object at rest remains at rest, and an object in motion continues in uniform motion unless acted upon by a net external force.

3.  Explain the principle of conservation of momentum.

Answer: The principle of conservation of momentum states that in an isolated system, the total momentum remains constant before and after a collision, provided no external forces act on it.

4.  What is work done by a force? Provide the formula.

Answer: Work done is the energy transferred when a force moves an object over a distance. It is calculated using the formula W=F⋅d⋅cos⁡(θ)
Where W is work, F is the force applied, dd is the distance moved, and θ is the angle between the force and the direction of motion.

5.  Define gravitational potential energy.

Answer: Gravitational potential energy is the energy possessed by an object due to its position in a gravitational field. It is calculated using the formula: PE=mgh.
Where m is mass, g is the acceleration due to gravity, and h is the height above a reference point.

6.  State Ohm's Law and its significance.

Answer: Ohm's Law states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, expressed as V=IR, where V is voltage, I is current, and R is resistance. It helps in understanding how electrical circuits function.

7.  What is the principle of superposition of waves?

Answer: The principle of superposition states that when two or more waves overlap in space, the resultant displacement at any point is equal to the sum of the displacements of the individual waves.

8.  Describe the concept of simple harmonic motion (SHM).

Answer: Simple harmonic motion is a type of periodic motion where an object moves back and forth around an equilibrium position. The motion is characterised by a restoring force proportional to the displacement from the equilibrium position, following Hooke's Law.

9.  What is the Doppler effect?

Answer: The Doppler effect is the change in frequency or wavelength of a wave concerning an observer moving relative to the wave source. It is commonly observed in sound waves as a change in pitch when a sound source approaches or recedes from an observer.

10.  Explain the laws of reflection and refraction.

Answer:

• Laws of Reflection: 

1) The angle of incidence is equal to the angle of reflection. 

2) The incident ray, reflected ray, and the normal at the point of incidence all lie in the same plane.

• Laws of Refraction: 

1) The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant (Snell's Law). 

2) The incident ray, refracted ray, and the normal to the surface at the point of incidence all lie in the same plane.

Here are some important questions for Class 11 Physics. For a deeper understanding of each chapter, please go through the Chapter-wise Important Questions table. This resource will assist you in understanding the key concepts and important questions in each chapter and preparing effectively for your exams.

How Does Class 11 Physics Important Questions Help you with Exams?

• Important questions highlight the essential topics and concepts that are frequently tested, allowing students to concentrate their studies on what matters most.

• By practising these questions, students can deepen their understanding of fundamental principles and how they apply them to various problems.

• Familiarity with important questions prepares students for the types of questions they may encounter in exams, reducing anxiety and boosting confidence.

• These questions serve as a useful tool for quick revisions, helping students recall critical information efficiently before exams.

• Practising important questions allows students to gauge their speed and accuracy, improving their time management skills during actual exams.

• Students can identify areas where they need more practice, allowing them to allocate their study time effectively to strengthen their weak points.

• Important questions often require applying concepts to solve problems, enhancing analytical and problem-solving skills critical for success in physics.

Focusing on important questions in Class 11 Physics plays a vital role in exam preparation. These questions not only help students identify and understand key concepts but also enhance their problem-solving and critical-thinking skills. By practising these targeted questions, students can improve their confidence, manage their time effectively, and pinpoint areas that require further attention. Ultimately, this strategic approach to studying equips students with the tools they need to excel in their exams, making the learning process more efficient and effective. Embracing the importance of these questions can lead to a deeper comprehension of physics, paving the way for academic success.

CBSE Class 11 Physics Chapter-wise Important Questions

CBSE Class 11 Physics Chapter-wise Important Questions and Answers cover topics from all 14 chapters, helping students prepare thoroughly by focusing on key topics for easier revision.

Additional Study Materials for Class 11 Physics