1

A uniform solid cube material 10cm on each side of mass 700g is submerged in water. which of the following best described the behavior of the cube water?

A

the cube will melt after a period of time

B

the cube will float

C

the cube will sink in water

D

the cube will rest at an equilibrium position in water

CORRECT OPTION:
b

For the uniform cube 10cm volume = 10 x 10 x 10 = 10^{3} cm^{3}

Mass = 700g

∴ density = (Mass)/Volume = (700)/100 = 0.7gcm^{-3}

since the density is less than the density of water, the cube will float

Mass = 700g

∴ density = (Mass)/Volume = (700)/100 = 0.7gcm

since the density is less than the density of water, the cube will float

2

At low humidity in an environment, the human skin is usually?

A

damp and rough

B

damp and smooth

C

dry and rough

D

dry and smooth

CORRECT OPTION:
c

3

If the relative density of gold is 19.2, the volume of 2.4kg of gold is?

A

8.00 x 10^{-3} m^{3}

B

1.25 x 10^{-4} m^{3}

C

1.92 x 10^{-4} m^{3}

D

4.61 x 10^{-3} m^{3}

CORRECT OPTION:
b

R.D = (density of the subs)/density of water

19.2 =(P)/10^{3}; ∴P = 19.2 X 10^{3}

But Vol. = (Mass)/density = (2.4)/19.2 x 10^{3}

= 1.25 x 10^{-4} M^{3}

19.2 =(P)/10

But Vol. = (Mass)/density = (2.4)/19.2 x 10

= 1.25 x 10

4

The thermometric property of a constant volume thermometer is?

A

change in volume

B

differential expanssion

C

change in pressure

D

change in length

CORRECT OPTION:
c

The thermometric property of a constant volume thermometer is change in pressure with temperature

5

An immersion heater rated 2.0A, 240V is used to boil water from temperature 52°c to 100°c. If the mass of the water is 2.5kg. determine the time taken to boil the water.

[specific heat capacity of water = 4.2 x 10^{3} jkg^{-1} k^{-1}]

[specific heat capacity of water = 4.2 x 10

A

1.05 x 10^{3}s

B

1.05 x 10^{5}s

C

1.05 x 10^{2}s

D

1.05 x 10^{4}s

CORRECT OPTION:
a

Power of heater = lvt = 2 x 240 x t

heat required to boil the water = Mct = 2.5 x 4.2 x 10^{3} x (100.52) = 2.5 x 4. 2 x 10^{3} x 48

2 x 240 x t = 2.5 x 4.2 x 10^{3} x 48

∴ t = (2.5 x 4.2 x 10^{3} x 48)/2 x 240

= 1050s or 1.05 x 10^{3}s

heat required to boil the water = Mct = 2.5 x 4.2 x 10

2 x 240 x t = 2.5 x 4.2 x 10

∴ t = (2.5 x 4.2 x 10

= 1050s or 1.05 x 10

6

The thermos flask is designed to?

A

prevent heat loss or gain by conduction, convection amd radiation

B

store hot tea or water

C

prevent heat gain by conduction, convection and radiation

D

prevent head lost conduction, convention and radiation

CORRECT OPTION:
a

7

what is likely to happen if the glass of a thermometer expands more upon heating than the liquid inside?

A

the glass will break

B

the glass will shrink

C

the liquid will rise up in the stem

D

the liquid will go down in the stem

CORRECT OPTION:
d

8

A drop of petrol makes a finger colder than a drop of water would because?

A

petrol takes its latent heat of veporization from the finger

B

petrol takes its latent heat of fusion from the finger

C

water is more viscious than petrol

D

water has higher surface tension dan petrol

CORRECT OPTION:
a

9

A cell of internal resistance r is connected to an external resistor R. The conductor for maximum power transfer is?

A

R < r

B

R = r

C

R = 2r

D

R > r

CORRECT OPTION:
d

p is the time rate of expending energy. for electrical energy, P = IV; 1^{2}R or (V)/R. For a cell of constant e.m.f (voltage) maintaining constant current(1) through the circuit, P α R; OR (1)/R.

Again for maxi. power,p α R

And with respect to the opinion, maxi power would be transferred when R>r:not necessarily R = 2r

Again for maxi. power,p α R

And with respect to the opinion, maxi power would be transferred when R>r:not necessarily R = 2r

10

The production and type of charge of a body can only be accounted for by the?

A

deficiency or surplus of electrons

B

equibrium in protons and neutrons

C

deficiency or surplus of protrons

D

deficiency or surplus of neutrons

CORRECT OPTION:
a

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