Level (I)
Level (I)
Level (I)
velocity of the liquid)is 2. The length of a rod is measured as 35.3cm then the
a) M 1L2T 1 b) M 1LT
1 1
graduations on the scale are up to
a)1cm b)1mm c)0.01mm d)0.1mm
c) M 0 L0T 1 d) M 0 L0T 0
3. If L 2.06cm 0.02cm, B 1.11cm 0.03cm,
40. If force (F), work (W) and velocity (V) are taken as
then L B equals to
fundamental quantities then the dimensional
a) 3.17cm 0.05cm, b) 2.06cm 0.05cm,
formula of time (T) is
c) 3.17cm 0.02cm, d) 3.17cm 0.03cm,
a) W 1F 1V 1 b) W 1F 1V 1
4. The radius of sphere is measured as 5.2 0.2 cm
c) W 1F 1V 1 d) W 1F 1V 1
then the percentage error in volume of the ball is
41. If Force F, Mass M and time T are chosen as a)11% b)4% c)7% d)9%
fundamental quantities the dimensional formula for 5. If the length and breadth of a plate are 5.2 0.2
length, is
cm and 4.0 0.1 cm then the absolute error in
a) FMT b) FM 1T 2
measurement of area is
c) FL2T 2 d) F 1L2T 2 2 2 2 2
a)10 cm b)11 cm c)12 cm d)1.3 cm
42. If force F, Length L and time T are chosen as 6. If the length of a cylinder is measured to be 8.28 cm
fundamental quantities, the dimensional formula with an error of 0.01cm then the percentage error
for Mass is in measured length is nearly
a) FLT b) F 1L1T 2 a)0.4% b)0.2% c)0.1% d)0.5%
7. A student performs experiment with simple
c) F 2 L2T 2 d) F 1L1T 2 pendulum and measures time for 10 vibrations. If
LEVEL-I(C.W)-KEYS he measures the time for 100 vibrations, the error
1. c 2. c 3. d 4. c 5. a in measurement of time period will be reduced by a
6. c 7. a 8. b 9. d 10. c factor of
11. a 12. b 13. d 14. b 15. d a)10 b)90 c)100 d)1000
16. b 17. c 18. a 19. b 20. b 8. If L1 (3.03 0.02) m and L2 (2.01 0.02)m
21. c 22. b 23. c 24. c 25. d
26. c 27. c 28. a 29. c 30. b then L1 2 L2 is (in m)
31. d 32. a 33. a 34. c 35. b a)7.05 0.06 b)6.05 0.06
36. a 37. c 38. c 39. d 40. d c)6.05 0.02 d)7.05 0.02
41. b 42. d
9. A body travels uniformly a distance of
13.8 0.2 m in a time 4.0 0.3 s then the
LEVEL-I(H.W) velocity of the body is
a) 3.45 0.2 ms 1 b) 3.45 0.3 ms 1
ACCURACY, PRECISION,TYPES OF
c) 3.45 0.4 ms 1 d) 3.45 0.5 ms 1
ERRORS AND COMBINATION OF
10. The pressure on a square plate is measured by
ERRORS measuring the force on the plate and the length of
the sides of the plate. If the maximum error in
measurement of force and length are respectively
4% and 2% then the maximum error in 23. The dimensional formula for the product two
Measurement of pressure is physical quantities P and Q is L2T 2 the
a)1% b)2% c)6% d)8%
SIGNIFICANT FIGURES & dimensional formula of P/Q is T 2 the and Q
ROUNDING OFF respectively are
11. 2.34 obtained by rounding off the number a)distance and velocity
a)2.346 b)2.355 c)2.335 d)2.334 b)distance and acceleration
12. The number of significant figures in 0.0006032 is c)displacement and velocity
a)7 b)4 c)5 d)2 d)displacement and force
13. The radius of disc is 1.2 cm, its are according to idea 24. The fundamental physical quantities that have same
of significant figures is dimensions in the dimensional formula of force and
2 2 2 2
a)4.5216 cm b)4.521 cm c)4.52 cm d)4.5 cm Energy are
14. When Energy is expressed in erg the no significant a)mass, time b)time, length
figure is four. If it is expressed joule the no of c)mass, length d)time, mole
significant figures will become 25. If is rigidity modulus, r is the radius, l is the length
a)9 b)5 c)1 d)4 2lc
and C is the moment of the couple then has
15. 58.97 is r 4
a)7.679 b)7.68 c)7.6 d)7.7 the dimensions of
16. A stick has a length of 12.132cm and other stick has a)Angle b)Mass c)Length d)Frequency
a length of 12.4cm then total length of the stick is PRINCIPLE OF HOMOGENEITY
a)24.53cm b)24.5cm c)2.45cm d)2.453cm 26. The acceleration of an object varies with time as
17. The respective number of significant figure the a AT 2 BT C taking the unit of time as 1 sec
3
number 23.023,0.0003 and 21x10 are and acceleration as ms-2 then the units of A,B,C
a)5,1,2 b)5,1,5 c)5,5,2 d)4,4,2 respectively are
18. The Number of significant figures in 5.69 x1015 kg is a) ms 3 , ms 2 , ms 1 b) ms 2 , ms 1, ms
a)1 b)2 c)3 d)4 c) ms 1 , ms 2 , ms 3 d) ms 4 , ms 3 , ms 2
19. The value of 124.2+52.487 with due regard to
A
significant places is 27. If log Bx C is dimensionally true, then
B
a)176.69 b)176.7 c)176 d)177
(here is the coefficient of viscosity and x is the
9.27
20. The value of with due regard to significant distance)
41
a)C is dimensionless constant
figures is
b)B has dimensions of -1 in length
a)0.226 b)0.23 c)0.2 d)0.2261
c)The dimensional formula of A is ML2T 1
21. When 57.986 is rounded off to 4 significant figures,
d)All are true
then it becomes
28. If the velocity (v) of a body in time ‘t’ is given by
a)58 b)57.00 c)57.90 d)57.99
UNITS AND DIMENSIONS ALFORMULAE V AT 3 BT 2 CT D then the dimension of C
22. If ' L ' is length of simple pendulum and ' g ' are
acceleration due to gravity then the dimensional a) LT 1 b) LT 2 c) LT 3 d) LT 4
1
1 2 Pr 4
formula for is same as that for 29. In the relation V where the letters have
8l
g
a)Frequency b)Velocity there usual meanings the dimensions of V are
c)Time period d)Wavelength a) M 0 L3T 0 b) M 0 L3T 1 c) M 0 L3T 1 d) M 1L3T 0
30. If the acceleration due to gravity is 10ms-2 and the 39. If pressure (P), velocity (V) and time (T) are taken as
units of length and time are changed to kilometer the fundamental quantities, then the dimensional
and hour respectively the numerical value of formula of force is
acceleration is a) P1V 1T 1 b) P1V 2T 1
a)36000 b)72000 c)36000 d)129000
31. The magnitude of Energy is 100J. What will be its c) P1V 1T 2 d) P1V 2T 2
value if the units of mass and time are doubled and LEVEL-I(H.W)KEY
that of length is halved?
1. a 2. d 3. a 4. a 5. d
a)100J b)200J c)400J d)800J 6. c 7. a 8. a 9. b 10. d
32. If the units of mass and velocity are increased by 11. c 12. b 13. d 14. d 15. a
two times then the unit of momentum will be 16. b 17. a 18. c 19. b 20. b
increased by 21. d 22. c 23. b 24. a 25. a
a)400% b)200% c)300% d)100% 26. d 27. d 28. b 29. b 30. d
7
31. d 32. c 33. c 34. b 35. a
33. SI unit and CGS unit of a quantity vary by 10 times, 36. a 37. a 38. c 39. d
it is
a)Boltzmann’s constant b)Gravitational constant
c)Planck’s constant d)Angular momentum
34. The initial velocity f a particle is given by
u 2 v 2 2 gx where x is the distance covered. If u=
18kmh 1 ,g=1000 cm / s 2 =150cm then v=m/s
a) 45 b) 55 c) 35 d) 65
35. The equation which is dimensionally correct among
the following is
1
a) v u at b) v ut at
2
c) s ut at d) t s av
3
p
36. The dimensions of in the relation v
(where v is velocity, p is pressure, is pressure,
is density)
a)Dimensionless b) LT 1 c) ML1T 2 d) ML3
37. Taking frequency f, velocity (v) and Density ( ) to
be the fundamental quantities then the
Dimensional formula for momentum will be
a) v 4 f 3 b) v3 f 1 c) vf 2 d) 2v 2 f 2
38. If momentum (p),Mass(M), Time (T) are chosen as
fundamental quantities then the dimensional
formula for length is
a) P1T 1M 1
b) P1T 1M 2
c) P T M
1 1 1
d) P T
2 2
M1