PHYSICS (UT-1)
CLASS-XI (SET-2)
Session — 2022-23
Time : 1 Hour
M.M-20
Read the following instructions very carefully.
• This question paper comprises two sections A & B.
• There are 8 questions in the question paper.
• Section A – Question no. 1 to 4 carries 2 marks each.
• Section B – Question no. 5 to 8 carries 3 marks each.
• There is no overall choice in the question paper.
SECTION — A (2-Marks)
(1) Which quantity among Work, Linear momentum, Angular momentum and Impulse has same dimension as that of plank’s constant?
(2) What is the dimensional analysis? State it’s two application?
(3) Check the dimensional consistency in case of the following equations.
(i) E=mc²
(ii) T=2π√(l/g)
(4) Name the physical quantities whose dimensional formulae are as follows:
(i) [ML2T-3]
(ii) [ML-1T-2]
SECTION — B (3-MARKS)
(5) By the use of dimensions, show that energy per unit volume is equal to the pressure.
(6) An electric bulb has a power of 500W. Express it in CGS units.
(7) A planet moves around the sun in nearly circular orbit. Its period of revolution is T depends upon;
(i) Radius ‘r’ of the orbit,
(ii) mass (M) of the sun and,
(iii) the gravitational constant (G).
Show dimensionally that T²∝r³
(8) (a) Add 7.21, 12.141 and 0.0028 and express the result to an appropriate number of significant figures.
(b) 5.74g of a substance occupies 1.2 cm³. Express its density keeping significant figure in view.