Young's modulus of steel is 1.9 x 10¹¹ N / m². When expressed in CGSunits of dyne / cm ² , it will be equal to (1N =10 ⁵ dyne, 1 m ² = 10⁴ cm²)

1

(a)

1.9 x 10¹⁰

(b)

1.9 x 10¹¹

(c)

1.9 x 10¹²

(d)

1.9 x 10¹³

The mean length of an object is 5 cm. Which of the following measurements is most accurate?

1

(a)

4.9 cm

(b)

4.805 cm

(c)

5.25 cm

(d)

5.4 cm

The number of significant figures in 0.06900 is _____.

1

(a)

5

(b)

4

(c)

3

(d)

2

The numbers 2.745 and 2.735 on rounding off to 3 significant figures will give _____.

1

(a)

2.75 and 2.74

(b)

2.74 and 2.73

(c)

2.75 and 2.73

(d)

2.74 and 2.74

A lift is coming from 8th floor and is just about to reach 4th floor. Taking ground floor as origin and positive direction upwards for all quantities, which one of the following is correct?

1

(a)

x<0, v<0, a>0

(b)

x>0, v<0, a<0

(c)

x>0, v<0,a>0

(d)

x>0,v>0,a<0

At a metro station, a girl walks up a stationary escalator in time t₁ If she remains stationary on the escalator, then the escalator take her up in time t₂ .The time. taken by her to walk up on the moving escalator will be

1

(a)

\(\left(t_{1}+t_{2}\right) / 2\)

(b)

\(t_{1} t_{2} /\left(t_{2}-t_{1}\right)\)

(c)

\(t_{1} t_{2} /\left(t_{2}+t_{1}\right)\)

(d)

t₁ = t₂

Which one of the following statements is true?

1

(a)

A scalar quantity is the one that is conserved in a process

(b)

A scalar quantity is the one that can never take negative values

(c)

A scalar quantity is the one that does not vary from one point to another in space

(d)

A scalar quantity has the same value for observers with different orientation of the axes

The component of a vector r along X-axis will have maximum value if

1

(a)

r is along positive y-axis

(b)

r is along positive x-axis

(c)

r makes an angle of 45° with the x-axis

(d)

r is along negative y-axis

In a two dimensional motion, instantaneous speed V_o is a positive constant. Then, which of the following are necessarily true?

1

(a)

The acceleration of the particle is zero

(b)

The acceleration of the particle is bounded

(c)

The acceleration of the particle is necessarily in the plane of motion

(d)

The particle must be undergoing a uniform circular motion

Figure shows the orientation of two vectors u and v in the xy-plane

\(\text { If } \mathbf{u}=a \hat{\mathbf{i}}+b \hat{\mathbf{j}} \text { and } \mathbf{v}=p \hat{\mathbf{i}}+q \hat{\mathbf{j}}\) Which of the following is correct?

1

(a)

a and p are positive while band q are negative

(b)

a, p and b are positive while q is negative

(c)

a, q and b are positive while p is negative

(d)

a, b, p and q are all positive