SUBJECT: IIT-PHYSICS COURSE: GROWTH (XI) ELP No.

-01

Note: (*) → Multiple Correct Type Question

Total Marks: 31 Max. Time: 21 min.

Single Correct Questions ('–1' negative marking) Q.1 to Q.9 (3 marks, 2 min.)
Multiple Correct Questions (‘-2’ negative marking) Q.10 (4 marks, 3 min.)
(There is partial marking in multiple correct questions)

1. Which of the following is not the unit of length:

(A) micron (B) light year
(C) angstrom (D) radian

2. Which of the following is not a unit of work (Work = Force × Displacement):

(A) W.s (B) Kg.m/s
(C) N.m (D) J

3. N Kg-1 is the unit of:

(A) velocity (B) momentum
(C) angular momentum (D) acceleration

4. The dimensional formula for angular momentum L is (Angular Momentum = Mass × Velocity × Distance):
(A) [M°L°T0] (B) [M1L2T-1]
(C) [M1L-1T-1] (D) [M0L-1T°]

5. The product PV has the dimensions: (‘P’ denotes pressure and ‘V’ denotes volume.)
(A) [M1 L-1 T-2] (B) [M1 L2 T-1]
(C) [M L T ]
1 2 -2
(D) [M1 L2 T-3]

6. Which of the following physical quantities represents the dimensional formula [M 1L–2T–2] ?
(A) Energy / Area (B) Pressure
(C) Force × length (D) Pressure per unit length

7. Using mass (M), length (L), time (T), and electric current (A) as fundamental quantities, the
1 q q
dimensions of permittivity (0) will be ( F =  1 2 2 ):
4 0 r
(A) [M LT-1 A-1] (B) [M LT-2 A-2]
(C) [M L T A ]
-1 -3 4 2
(D) [M2 L-2 T-2 A]
8. Which of the following combinations of three dimensionally different physical quantities P, Q, R can
never be a meaningful quantity?
(A) PQ – R (B) PQ / R
(C) (P – Q) / R (D) (PR – Q2) / QR

KT01_6018 1
9. If A and B have different dimensions then the correct relation according to dimensional principles
will be:
(A) A + B (B) A – B
(C) A/B (D) eA/B

10*. Consider three physical quantities x, y and z. Operations x + y and y–z is valid with these physical
quantities. Which of the following conclusions can you make?
(A) The operation x ± z is also valid.
(B) If dimension of any of the three is known, dimension of other two can be predicted.
(C) If dimension of product of any two of them is known, dimension of all of them can be predicted.
(D) If dimension of quotient of any two of them is known, dimension of all of them can be predicted.

(ABC) 10. (C) 9. (C) 8.

(C) 7. (D) 6. (C) (B) 5. (D) 4. 3. (B) 2. (D) 1.
ELP No.-01
ANSWER KEY

KT01_6018 2
SUBJECT: IIT-PHYSICS COURSE: GROWTH (XI) ELP No.-02

Total Marks: 31 Max. Time: 21 min.

Single Correct Questions ('–1' negative marking) Q.1 to Q.9 (3 marks, 2 min.)
Subjective Type Questions (No negative marking) Q.10 (4 marks, 3 min.)

( − t )
2

1. The time dependence of a physical quantity p is given by p = p0e where  is constant and t is
time. The constant  :
(A) is dimensionless (B) has dimensions T–2
(C) has dimensions T2 (D) has dimensions of p

2. In function F = v2 sin(t), F denotes force, v velocity and t time. The dimensional formula of 2 is
same as dimensional formula of:
(A) acceleration due to gravity (B) work done
(C) atmospheric pressure (D) power

X
3. Force F = + C is a dimensionally correct relation, then X will have dimension:
density
(A) MLT-2 (B) MLT-3 (C) ML2T-3 (D) M2L-2T-2

a a – t2
4. The dimensions of in the equation P = , (where P is pressure, x is distance and t is time)
b bx
are:
(A) [M2L T–3] (B) [MT–2] (C) [LT–3] (D) [ML3T–]

A x
5. The potential energy of a particle varies with distance x from a fixed point as U = where A
x + B2
and B are constants. Then the dimension of AB2 is:
(A) ML3/2T–2 (B) ML7/2T–2 (C) M2L5/2T–2 (D) Dimensionless

6. Which relation is dimensionally INCORRECT?

force
(Given, surface tension = )
length
1 1
surface tension
(A) Pressure = (B) Velocity = (displacement) 2 (Acceleration)2
length
1
−
(C) Volume = (Area)2 (length)−1 (D) Height = (Velocity)(Accleration) 2

7. A gas bubble oscillates with a time period T proportional to P a db Ec where P is pressure, d is the
density and E is the energy. The values of a, b & c are
3 1 1 5 1 1
(A) a = ,b = – ,c = (B) a = – ,b = ,c =
2 3 2 6 3 2
5 1 1 3 1 1
(C) a = – ,b = ,c = (D) a = ,b = – ,c =
6 2 3 2 3 2
KT01_6019 1
8. The velocity of a body falling freely under gravity g through height h is v = kg ahb. The values of a and
b by method of dimension are :
(A) a = 1, b = 1 (B) a = 1/2, b = 1/2
(C) a = 1/2, B = 1 (D) a = 1, b = ½

9. If the radiation pressure, velocity of light and radiation energy per unit area per sec are represented
by P, C and Q respectively. Then what are the value of the non-zero whole numbers x, y and z such
that the quantity PxQyCz becomes dimension less:
(A) x = 1, y = 1, z = -1
(B) x = 1, y = -1, z = 1
(C) x = -1, y = 1, z = 1
(D) x = y = z = 1

10. The volume of an object as a function of time is calculated by V = At3 + B/t, where t is time measured
in seconds and V is in cubic meters. Determine the dimensions of the constants A and B.

L3T–3, L3T1 10. (B) 9. (B) 8.

(C) 7. (D) 6. (B) (D) 4. (B) 5. 3. (C) 2. (B) 1.
ELP No.-02
ANSWER KEY

KT01_6019 2
SUBJECT: IIT-PHYSICS COURSE: GROWTH (XI) ELP No.-03

Total Marks: 33 Max. Time: 23 min.

Single Correct Questions ('–1' negative marking) Q.1 to Q.7 (3 marks, 2 min.)
Subjective Type Questions (No negative marking) Q.8 to Q.10 (4 marks, 3 min.)

1. Which of the following quantities cannot enter into the list of fundamental quantities in any system
of units?
(A) Mass, Time and Acceleration
(B) Length, Volume and Linear momentum
(C) Mass, Velocity and time
(D) Length, Force and Time

2. If the speed of light (c), acceleration due to gravity (g) and pressure (P) are taken as fundamental
units, the dimensions of gravitational constant (G) are:
(A) c2g3p2 (B) c0g2p–1
(C) c2g2p–2 (D) c0gp–3

3. If force (F), velocity (V) and time (T) are taken as fundamental units, the dimensions of mass are:
(A) [FVT–1] (B) [FVT-2] (C) [FV–1T–1] (D) [FV–1T]

4. Which relation CANNOT be derived dimensionally?

Force
(A) Pressure =
Area
(B) Volume = length × area
(C) Thermal energy = (momentum)2 (mass)–1
(D) Distance = velocity × time

5. Which of the following statements is correct about conversion of units, for example 1 m = 100 cm?
(A) Conversion of units have identical dimensions on each side of the equal sign but not the same
units.
(B) Conversion of units have different dimensions on each side of the equal sign but have same
unit.
(C) If a larger unit is used then numerical value of physical quantity is large.
(D) Due to conversion of units, physical quantity to be measured will change.

6. In a new unit system, 1 unit of time is equal to 10 second, 1 unit of mass is 5 kg and 1 unit of length
is 20 m. In this new system of units, 1 unit of energy is equal to:
Gm1m2 force F l
(Given, F = , surface tension = , modulus of elasticity = )
r 2
length A  l

1
(A) 20 Joule (B) Joule
20
(C) 4 Joule (D) 16 Joule
KT01_6020 1
7. If unit of mass, length, and time are doubled than unit of which of the following quantity will remain
unchanged?
(A) Energy (B) Surface tension
(C) Gravitational constant (D) Modulus of elasticity

8. The energy E of an oscillating body in simple harmonic motion depends on its mass m, frequency
n and amplitude A as E = k(m)x (n)y (A)z. Find the value of (2x + y + z).

9. Viscous force acting on a spherical ball is given by F = 6 rv, where r is radius of the ball, v is the
velocity of the ball and  is coefficient of viscosity. Dimensional formula of  is given by [] = MaL–bT–c.
Find the value of a + b + c.

10. The value of Stefan’s constant in CGS system is  = 5.67 × 10–5 erg s–1 cm–2 K–4. Its value in SI unit
is______.

5.67 × 10–8 Js–1 m–2 K–4 10. 3 9. 6 8.

(C) 7. (A) 6. (A) (D) 4. (B) 5. 3. (B) 2. (B) 1.
ELP No.-03
ANSWER KEY

KT01_6020 2