DPP-1

PHYSICS

IMPULSE

DPP-1

(UNITS,MEASUREMENTS & DIMENSIONS) 1.

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 the new system of units, 1 unit of energy is equal to: 1 Joule (C) 4 Joule (D) 16 Joule 20 A force of 6N and another of 8N can be applied together to produce the effect of a single force of: (A) 1 N (B) 11 N (C) 15 N (D) 20 N

(A) 20 Joule

2.

3.

Date:11/07/2016

(B)

a a − t2 in the equation P = where P is pressure, x is distance and t is The dimensions of b bx time, are: (A) [M2L T–3] (B) [MT–2] (C) [LT–3] (D) [ML3T–1] 2

4.

The time dependence of a physical quantity p is given by p = p 0 e ( − α t ) where α is constant and t is time. The constant α (A) is dimensionless (B) has dimensions T–2 2 (C) has dimensions T (D) has dimensions of p

5.

If area (A) velocity (v) and density (ρ) are base units, then the dimensional formula of force can be represented as. (A) Avρ (B) Av2ρ (C) Avρ2 (D) A2vρ

6.

Which of the following dimensions are correctly matched : (θ = temperature) (A) angular momentum – M1L2T–1 (B) Torque – M1L2T–2 1 –3 –4 (C) Stefan’s constant – M T θ (D) Planck’s constant – M1L2T–2

7.

Match the column : Quantity (A) Energy density (Energy per unit volume) (B) Force constant of a spring (C) Pressure

8.

In two systems of units, the relation between velocity, acceleration and force is given by v2 =

F1 v1ε 2 ,a2 = a1ετ , F2= , where ε and τ are constants then find in this new system ετ τ

m2 (a) m

L2 (b) L 1

1

Q.1

9.

Unit (P) Dyne/cm2 (Q) kg-m/s (R) Erg/cm2 (S) Pascal

A vector

E, m, L, G denote energy, mass, angular momentum & gravitation constant respectively. The dimensions of (A) angle

EL2 will be that of : m5 G 2 (B) length (C) mass

(D) time

10.

The dimensional formula for which of the following pair is not the same (A) impulse and momentum (B) torque and work (C) stress and pressure (D) momentum and angular momentum