1

Which of the following instruments is suitable for making the most accurate measurement of the internal diameter of a test tube?

A

metre rule

B

A pair of callipers

C

A micrometer screw gauge

D

A tape rule

CORRECT OPTION:
b

2

A particle of mass 2.5 x 10^{-6}kg revolving around the earth has a radial acceleration of 4 X 10^{7} ms^{-2}. What is the centripetal force of the particles?

A

6.25 x 10^{-14}N

B

1.60 x10^{-13}N

C

5.00 x 10N

D

1.00x10^{2}N

CORRECT OPTION:
d

F = ma = 2.5 x 10^{-6} x 4 x 10^{7} = 100N

3

An oscillating pendulum has a velocity of 2ms^{-1} at the equilibrium position O and velocity at same point P. Using the diagram above, calculate the height of P above O. (Take g = 10ms^{2})

A

5.0m

B

2.0m

C

0.4m

D

0.2m

CORRECT OPTION:
d

Kinetic energy at O = P.E at P 1/2mV = mgh

h = v^{}/2g = 0.2m

h = v

4

Which of the following are contact forces? I. Force of tension II. Force of fiction, III. Magnetic force III Force of reaction.

A

I,II and III only

B

I, II and IV only

C

I, III and IV only

D

II, III and IV only

CORRECT OPTION:
b

5

A plane inclined at an angle at 30^{o} to the horizontal has an efficiency of 50%. The force parallel to the plane required to push a load of 120 N uniformly up the plane is

A

40√3N

B

60N

C

120N

D

200N

CORRECT OPTION:
c

E = M.A/V.R ; 50/100 = M.A/2

M.A = 1; L/E = 1

E = L = 120N

M.A = 1; L/E = 1

E = L = 120N

6

The diagram above represents a portion of a micrometer screw 20 gauge. What is its reading?

A

3.70mm

B

3.67mm

C

3.50mm

D

3.33mm

CORRECT OPTION:
e

7

A girl whose mass is 55kg stands on a spring - weighing machine inside a lift. When the lift starts to ascend, its acceleration is 2ms1. What will be the reading on the machine? (Take g = ms^{-2})

A

66 kg

B

55 kg

C

44 kg

D

22 kg

CORRECT OPTION:
a

Reading = mg + ma = m(g + a) = 55(10 + 2)

= 660N = 66kg

= 660N = 66kg

8

Two forces each of 4 N act on the opposite sides of a rectangular plate as shown in the diagram above. Calculate the magnitude of g the couple acting on the plate.

A

6.4 Nm

B

3.2 Nm

C

1.6 Nm

D

0.8 Nm

CORRECT OPTION:
c

couple moment = F x d = 4 x 0.4 = 1.6Nm

9

A force F is applied to a body P as shown in the diagram above. If the body P moves through a distance r, which of the following represents the work done?

A

Fx

B

F^{cosθ}/_{x}

C

Fx tanθ

D

Fx sinθ

CORRECT OPTION:
e

10

An object R leaves a platform XY with a horizontal velocity of 7m^{-1} and lands at Q. lf it takes the same object 0.3s to fall freely from Y to P, calculate the distance PQ.(Take g = 1Oms^{2})

A

7.30m

B

2.55m

C

2.10m

D

1.65m

CORRECT OPTION:
c

D = v x t = 7 x 0.3 = 2.1m

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