Physics Test 8

Result

Physics Test 8

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
4 / -1

80 gm of water at 30 ºC is poured on a large block of ice at 0 ºC. The mass of ice that melts is

A
30 gm

B
80 gm

C
150 gm

D
1600 gm

Solution

Since the block of ice at 0 ºC is large, the whole of ice will not melt, hence final temperature is 0 ºC.

∴ Q₁ = heat given up by water in cooling up to 0 ºC

= ms Δθ = 80 × 1 × (30 – 0)

= 2400 cal

If m gm be the mass of ice melted, then

Q₂ = ML = m × 80

Q₁= Q₂

m × 80 = 2400 or m = 30 gm

Hence, option A is correct.
Question 2
4 / -1

The kinetic energy of rotation of diatomic gas at 27 ° C will be (k = 1.38 × 10^–23Joule/k)

A
2.07 × 10^–21 Joule/molecule

B
4.14 × 10^–21 Joule/molecule

C
6.14 × 10^–23 Joule/molecule

D
3.07 × 10^–23 Joule/molecule

Solution

A diatomic gas molecule possesses two rotational degrees of freedom
Hence, total rotational kinetic energy

= 2 × 1/2 kT= kT

= 1.38 × 10^–23 × 300

= 414 × 10^–23 J/molecule

= 4.14 × 10^–21 J/molecule
Question 3
4 / -1

The absolute temperature of a gas is increased 3 times. The root mean square velocity of the molecule will become –

A
3 times

B
9 times

C
(1/3) times

D
√3 times

Solution

V ∝ √T