Topic Unit and Dimensions, Class 11 Physics MCQ Quiz Test

MCQ 1:
The unit of power is -

kilowatt
kilowatt-hour
dyne
joule

MCQ 2:
In the S.I. system, the unit of temperature is -

degree centigrade
Kelvin
degree Celsius
degree Fahrenheit

MCQ 3:
Which of the following is not a unit for energy ?

Kilo watt hour
Newton- meter
(weber) (ampere)
None of these

MCQ 4:
In SI unit the angular acceleration has unit of -

Nmkg^–1
ms^–2
rad.s^–2
Nkg^–1

MCQ 5:
The unit of Stefan’s constant is -

Joule sec^–2 K^–4
Joule.sec.K^–4
Watt.m² K^–4
Watt. m^–2.K^–4

MCQ 6:
Surface tension has MKS unit of-

N/m
N/m²
Nm
Nm²

MCQ 7:
The M.K.S. units of coefficient of viscosity is-

kg m^–1s^–1
kg m s^–2
kg m² s^–1
kg^–1 m^–1 s²

MCQ 8:
Which of the following pairs have same dimensions –
(a) Torque and work
(b) Angular momentum and work
(c) Energy and moment of inertia
(d) Light year and wavelengths

a and b
a and d
b and c
a, b, and d

MCQ 9:
If E, M, J and G denote energy , mass , angular momentum and gravitational constant then EJ²/M⁵G² has the dimensions of –

length
angle
mass
time

MCQ 10:
The dimensional formula for angular momentum is –

ML²T^–2
MLT^–1
ML²T^–1
M⁰L²T^–2

MCQ 11:
Vander waal's gas equation is [P + a/V²] (V–b) = RT. The dimensions of constant a as given above are –

M L⁴ T^–2
M L⁵ T^–2
M L³ T^–2
M L² T^–2

MCQ 12:
For 10^{(at + 3)}, the dimension of a is-

M⁰ L⁰ T⁰
M⁰ L⁰ T¹
M⁰ L⁰ T^–1
None of these

MCQ 13:
The velocity of a moving particle depends upon time t as v = at + b/(t+c). Then dimensional formula for b is –

[M⁰ L⁰ T⁰]
[M⁰ L¹ T⁰]
[M⁰ L¹ T^–1]
[M⁰ L¹ T^–2]

MCQ 14:
Which of the following is the most accurate measurement ?

3 × 10^–2 cm
0.030 cm
300 × 10^–4 cm
30 × 10^–3 cm

MCQ 15:
In arithmetic 17.8 x 3.1143 = 55.4354. But as a result of experimental measurements the best way to express the product is -

55.3454
55.4
55.44
55.435

MCQ 16:
A wave is represented by y = a sin (At – Bx + C) where A, B, C are constants. The Dimensions of A, B, C are

T^–1, L, M⁰L⁰T⁰
T^–1, L^–1, M⁰L⁰T⁰
T, L, M
T^–1, L^–1, M^–1

MCQ 17:
The dimensional formula of propagation vector (k) is

[M⁰LT^–1]
[M⁰L^–1T⁰]
[M¹ L^–1 T⁰]
[M^–1 L^–1T⁰]

MCQ 18:
Express length L in terms of G, h and c-

G^–1/2, h^1/2 c^1/2
G^1/2 h^1/2 c^–5/2
G h c
G^1/2 h^1/2 c^–3/2

MCQ 19:
If x = at + bt², where x is in metre and t in hour (hr), then unit of b will be -

m²/hr
m
m/hr
m/hr²

MCQ 20:
The equation of a wave is given by y = A sin ω {x /v – k} t ; where ω is the angular velocity and v is the linear velocity . The dimensions of k is

LT
T
T^–1
T²

MCQ 21:
The equation of the stationary wave is y = 2A sin (2πct/λ) cos (2πx/λ). Which of the following statements is wrong ?

the unit of ct is same as that of λ
the unit of x is same as that of λ
the unit of 2π c/λ is same as that of 2πx/λt
the unit of c/λ is same as that of x/λ

MCQ 22:
If the units of length and force are increased four times, then the unit of energy will -

becomes 8 times
becomes 16 times
decrease 16 times
increase 4 times

MCQ 23:
If the units of length , velocity and force are half, then the units of Power will be –

doubled
halved
quadrupled
remain unaffected

MCQ 24:
The distance covered by a particle in time t is given by x = a + bt + ct² + dt³. The dimensions of a and d are –

L, T^–3
L, LT^–3
L⁰, T³
None of these

MCQ 25:
Choose the wrong statement-

all quantities can be expressed dimensionally in terms of the fundamental quantities
a fundamental quantity cannot be represented dimensionally in terms of the rest of fundamental quantities
the dimension of a fundamental quantity, in other fundamental quantities is always zero
the dimension of a derived quantity isnever zero in any fundamental quantity

MCQ 26:
The period of a body under S.H.M. is represented by : T ∝ P^aD^bS^c, where P is pressure, D is density and S is surface tension, then the values of a, b, and c are -

–3/2, 1/2, 1
–1, –2, 3
1/2, –3/2, –1/2
1, 2, 1/3

MCQ 27:
The surface tension of a liquid is 70 dynes/cm. It may be expressed in M.K.S. system as-

70 N/m
7 × 10^–2 N/m
7 × 10² N/m
7 × 10³ N/m

MCQ 28:
What is the percentage error in the measurement of time period of a pendulum if maximum errors in the measurement of λ and g are 2% and 4 % respectively -

6%
4%
3%
5%

MCQ 29:
The error in the measurement of volume of sphere is 1.5 %. The error in the measurement of its diameter is -

1%
2%
0.5%
1.5 %

MCQ 30:
The radius of a thin wire is 0.16 mm. The area of cross-section taking significant figure into consideration in square millimetres is -

0.0804
0.080
0.08
0.080384