SPSC PHYSICS 25 YEARS PAST PAPERS
SPSC 5 years Past Papers Click here
چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
- 2072 J
- 1904 J
- 2240 J
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
To find the increase in internal energy, we can use the equation:
ΔU = Q - W
where ΔU is the change in internal energy, Q is the heat energy added (which is the latent heat of vaporization in this case), and W is the work done.
Given:
Q = 2240 J (latent heat of vaporization of water per gram)
W = 168 J (work done in the process of vaporization)
Now, we can plug in the values:
ΔU = Q - W
= 2240 J - 168 J
= 2072 J
- 0
- 1.64 × 10^38kgm^3
- 1.64 kgm^3
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
To calculate the moment of inertia of the Earth about its diameter, we can use the formula for the moment of inertia of a sphere:
I = (2/5)MR^2
where:
I = moment of inertia
M = mass of the Earth (10^25 kg)
R = radius of the Earth (diameter/2 = 12800 km / 2 = 6400 km = 6.4 × 10^6 m)
Plugging in the values, we get:
I = (2/5) × 10^25 kg × (6.4 × 10^6 m)^2
= (2/5) × 10^25 kg × 4.096 × 10^13 m^2
= 1.6384 × 10^38 kg m^2
≈ 1.64 × 10^38 kg m^2
- 500m/s
- 400m/s
- 300m/s
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
Explanation
To calculate the velocity attained by the rocket, we can use the equation:
F × t = m × Δv
where:
F = force applied (5 × 10^5 N)
t = time (20 s)
m = mass of the rocket (2 × 10^4 kg)
Δv = change in velocity (final velocity - initial velocity)
Since the rocket starts from rest, the initial velocity is 0. Therefore, Δv = final velocity.
Rearranging the equation to solve for Δv, we get:
Δv = F × t / m
= (5 × 10^5 N) × (20 s) / (2 × 10^4 kg)
= 500 m/s