V.S.
VIDYALAYA:: SUNABEDA
UNIT TEST-2 (2023-24)
PHYSICS (042)
CLASS-XI
Time allowed: 1½ Hours Maximum Marks: 40
General Instructions :
(i) All questions are compulsory. There are 20 questions in all.
(ii) This question paper has five sections: Section A, Section B, Section C, Section D and
Section E.
(iii) Section A contains SEVEN questions of one mark each, Section B contains THREE
ASSERTIONS & REASONING questions of ONE marks each, Section C contains
FOUR questions of TWO marks each, Section D contains FOUR questions of THREE
marks each & Section E contains TWO questions of FIVE marks each.
SECTION-A (Very Short Answer)
1. What is the value of 1 Light year in terms of kilometer? 1
(a) 9.4610 12
(b) 9.4610 10
(c) 9.4610 15
(d) 9.4610 8
2. Name the physical quantities whose dimensional formulae are [ML 2 T-3] and [ML-1T-2]. 1
(a) power and force constant (b) power and pressure
(c) work and power (d) power and force
3. Subtract 4.5 104 from 3.9 105 with due regard to significant figures. 1
(a) 3.510 5
(b) 3.510 4
(c) 3.410 5
(d) 3.410 4
4. What is the ratio of their acceleration, if vt graph of two objects make angles of 30 and 1
60 with time axis?
(a) 3:1 (b) 1:3 (c) 1:2 (d) 2:1
5. The distance covered by a body is given by s=(t3+2t2+4t+8) m. What is the value of its 1
speed at t=2 sec?
(a)24 m/s (b) 32 m/s (c) 12 m/s (d) 20 m/s
6. The motion of a particle is described by the equation u=at, where the symbols have the 1
usual meanings. What is the distance travelled by it in 2 sec ?
(a) 4a (b) 8a (c) 2a (d) 6a
7. Which physical quantity gives the measurement of inertia? 1
(a) distance (b) mass (c) pressure (d) acceleration
SECTION-B (ASSERTIONS & REASONING)
In the following Questions, a statement of Assertion (A) is followed by a statement of
Reason (R). Choose the correct one:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true and R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
8. Assertion (A): Energy is a derived quantity. 1
Reason (R): It uses Length, Mass and Time as the basic quantities
9. Assertion (A): The speedometer of an automobile measures average speed of the 1
automobile.
Reason(R): Average velocity is equal to the total displacement per total time taken.
10. Assertion (A): When a blanket is beaten by a stick, the dust particles get removed. 1
Reason (R): Force applied on a body is directly proportional to the rate of change of
momentum.
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SECTION-C (SHORT ANSWER QUESTIONS)
11. Define 1 parsec. Find 1 parsec in kilometer. 2
12. a 2
a−t , where P = Pressure, t = time and 2
Find the dimension of in the equation P =
b bx
x= distance.
13. Define acceleration. When will acceleration zero if the displacement of a particle is given 2
by x = 6t2 –t3 ?
14. Define 1 N and 1kgwt. Derive a relationship between N and kgwt. 2
SECTION-D (SHORT ANSWER QUESTIONS)
15. A man walks on a straight road from his home to market 3 km away with a speed of 6 3
km/hr. Finding the market closed he instantly turns back and walks home with a speed of
9 km/hr. What are his average speed and average velocity?
(i) 0 to 50 minutes and (ii) 0 to 40 minutes
16. In a new system the units of mass, length and time are 100 kg, 1 km and 1hour 3
respectively.
What is the value of 1 N in the new system?
17. A body covers 12 m in 2nd second and 20 m in 4th second. How much distance will it 3
cover in 6 seconds after 4th second?
18. A force of 40 N gives an acceleration of 4 m/s 2on a body of mass m1 and 2 m/s2 on another 3
body of mass m2. What acceleration would it give if both masses are tied together? What
velocity will it acquire in 10 sec if the combined body was initially at rest?
SECTION -E (LONG ANSWER QUESTION)
19. (a) What is meant by principle of homogeneity? Derive an expression for centripetal force 5
’F’ acting on a body, if it depends on its mass ‘m’, radius of a circle ‘r’ and angular
speed ’ω’ of the body.
(b) Prove that v2 - u2 = 2as dimensionally correct.
20. 1 2 5
(a) Derive the equation of motion S = u t + at using the property of integration.
2
(b) The acceleration ‘a’ of a particle is given by a = (3t 2+2t+4) m/s2. If its initial velocity is
2 m/s, find its velocity at the end of 2 sec.
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