# CLASS XI PHYSICS IMPORTANT QUESTIONS

3 MARKS:
1) DISTINGUISH BETWEEN FUNDAMENTAL UNITS AND DERIVED UNITS.
2) WHAT ARE THE TWO TYPES OF COLLISION? EXPLAIN THEM.
3) STATE NEWTONS FIRST LAW OF MOTION.
4) TWO EQUAL FORCES ARE ACTING AT A PIONT WITH AN ANGLE OF 60 BETWEEN THEM. IF THE RESULTANT FORCE IS EQUAL TO 20√3N. FIND THE MAGNITUDE OF EACH FORCE.
5) WHAT ARE THE DIFFERENT TYPES OF EQUILIBIRIUM.
6) STATE THE UNIVERSAL LAW OF GRAVITATION.
7) DEFINE GRAVITATIONAL POTENTIAL.
8) WHAT IS REYNOLD’S NUMBER?
9) WHAT IS SURFACE TENTION?
10) DEFINE SIMPLE HARMONIC MOTION.
11) WHAT ARE DEGREES OF FREEDOM?
12) DEFINE SOLAR CONSTANT.

13) DEFINE POWER OF A LENS. WHAT ITS UNIT?
14) STATE TANGENT LAW.
15) WHAT IS THE DISTANE TRAVELLED BY SOUND IN AIR WHEN A TUNING FORK OF FREQUENCY 256HZ COMPLETES 25 VIBRATIONS? (THE SPEED OF SOUND IN AIR IS 343MS-I)

5 MARK:

1. WRITE ANY 5 RULES AND CONVENTIONS OF WRITING SI UNITS.
2. THE HORIZONTAL RANGE OF A PROJECTILE ID 4√3 TIMES ITS MAXIMUM HEIGHT. FIND THE ANGLE OF PROJECTION.
3. STATE THE LAW OF CONSERVATION OF ANGULAR MOMENTEM AND EXPLAIN IT WITH AN EXAMPLE.
4. STATE KEPLER’S LAW OF PLENTARY MOTION.
5. GIVE THE GRAPHICAL REPRESENTATION OF i)DISPLACEMENT ii) VELOCITY iii) ACCELERATION OF A PARTICLE EXUCUTING SHM. MENTION THE DIFFERENCES BETWEEN THEM.
6. What are the characteristics of progressive waves?
7. List out any 5 postulates of kinetic theory of gases.

10 MARK:

1. State and prove parallelogram law of vectors and discuss the special cases.
2. State and prove bernoulli’s theorem.
3. Derive Meyer’s relation.
4. Describe the working of angstrom pyrheliometer with diagram. (NOT FOR CBSE)