Class XI (Physics) Chapter 1 CBSE

Class XI                                                                                      

Subject: Physics                                                                                    Boards CBSE

1. Explain Rutherford α scattering experiment.                                                                 (2)
2. A stone and a feather dropped from the same height do not reach the ground at the same. Reason?                                                                                                                                              (2)
3. Match the following columns:                                                                                           (2)

Name	Major Contribution/Discovery
Archimedes	Ultra short radio waves
Albert Einstein	Explanation of photoelectric effect; Theory of relativity
J C Bose	Principle of buoyancy; Principle of the lever
Michael Faraday	Laws of electromagnetic induction

1. Match the Link Between Technology and Physics                                                         (2)
   
   

Technology	Scientific Principle
Sonar	Generation, propagation and detection of electromagnetic waves
Lasers	Light amplification by stimulated emission of radiation
Radio and television	Detection of cosmic radio waves
Telescope	Reflection of ultrasonic waves

1. Write differences between Gravitational forces and Electromagnetic forces.         (2)
2. Explain Strong Nuclear Force and Weak Nuclear Force.                                               (1)
3. A vehicle moving with the speed of 18kmh-1 covers ____m in 1s?                           (1)
4. Fill in the blanks by suitable conversions of units

1. 1 kgm²s^-2  = ____gcm²s^-2.
2. 1m = _____ly
3. 3.0ms^-2 = ____kmh^-2
4. G = 6.67 x 10^-11Nm²(kg)^-2 = (cm)³ s^-2 g^-1                                                                      (2)

1. With which method we can measure large distance of a planet or a star from the earth? Explain.     (2)
2. The sun’s angular diameter is measured to be 1920”. The distance D of the Sun from the Earth is 1.496x 10¹¹m. What is the diameter of the sun?                                                           (2)
3. What is the full form of NPL? What is it’s responsibility in our country?                   (1)
4. Write differences between accuracy and precision?                                                   (2)
5. What do you understand by Systematic errors? Explain and name them.                (1)
6. We measured the period of oscillation of a simple pendulum. In successive measurements, the readings turn out to be 2.63s, 2.56s, 2.42s, 2.71s and 2.8s.
   Calculate the absolute errors, relative error or percentage error.                            (2)
7. The temperatures of two bodies measured by thermometer are t₁ =20⁰C+0.5⁰C and t₂=50⁰C + 0.5⁰C. Calculate the temperature difference and error there in.                                         (2)
8.  Write number of significant figure in the following

1. 3.00
2. 123000
3. 2.308
4. 0.02308                                                                                                                         (2)

1. The SI unit of energy is J=kgm²s^-2; that of speed v is ms^-1 and of acceleration a is ms^-2. Which of the formulae for kinetic energy (K) given below can you rule out on the basis of dimensional arguments (m stands for mass of the body):

1. K=m²v³
2. K=(1/2)mv²
3. K=(3/16)mv²
4. K=(1/2)mv² + ma                                                                                                          (2)