NEB Grade XI Physics Paper
Subject: Physics Grade: XI
Subject: Physics Grade: XI
Year :2076(2019) Code:110(B)
Attempt all the questions:
Given data :
Acceleration due to gravity(g) =10 m/s²
Youngs modulus for copper=1.2x10¹¹Nm⁻²
Youngs modulus for steel=2x10¹¹Nm⁻²
Cubical expansivity of glass =1.2x10⁻⁵/⁰C
Cubical expansivity of mercury=18x10⁻⁵/⁰C
Specific heat capacity of copper=400JKg⁻¹K⁻¹
Specific heat capacity of water=4200JKg⁻¹K⁻¹
Ratio of molar heat capacities(γ)=1.4
Permittivity of free space(ε₀)=8.85x10⁻¹²C²N⁻¹m⁻²
Group (A) bishalkafle.com.np
1.Answer any 6 questions :
a. The energy of photon is given by E= hf. Find the dimension and unit of Planck's constant h, where f is the
frequency of radiation.
frequency of radiation.
b.From a flying aeroplane a body should be dropped in advance to hit the target, why?
c.A light body and a heavy body have the same momentum. Which one will have more Kinetic energy ? Explain
d.A person sitting in an artificial satellite of the earth feels weightlessness, but a person standing on the moon has weight though the moon is a satellite of the earth. Why?
e.The passengers in a small boat aren’t allowed to stand, why?
f.If the ice on the polar caps of the earth melts how will it affect the duration of the day?Explain.
g.Why does hot soup taste better than cold soup?
2.Answer any 2 questions:
a. The latent heat of vaporization is much larger than the latent heat of fusion of a substance, why?
b.Why does it take a longer time to dry wet clothes in rainy summer than in sunny winter?
c.The internal energy of compressed gas is less than that of a rarefied gas at the same temperature, why?
3.Answer any 1 question :
a. The sun is less bright in the morning and evening as compared to that of noon though it's distance from the observer is almost same, why?
b.When white light is dispersed by a prism,red light appears at the top of the spectrum whereas violet at the bottom, why?
4.Answer any 1 question:
a. Bits of paper are attracted to an electrified comb, even though they have no net charge. How is this possible?
b.Can two electric lines of force intersect each other? Explain.
Group (B )bishalkafle.com.np
5. Answer any 3 questions :
a. What is escape velocity? Derive an expression for it on the surface of the earth.
b.Define angle of friction and angle of repose.Establish a relation between them.
c.Define moment of inertia.Derive an expression for the moment of inertia if thin uniform rod about an axis through it's center and perpendicular to its length.
d.What is simple harmonic motion?Calculate the total energy of a particle executing simple harmonic motion.
6.Answer any 2 questions:
a. State Newton's law of cooling. Use it to find the specific heat capacity of a unknown liquid.
b.Derive an expression for the pressure exerted by an ideal gas on the basis of Kinetic theory.
c.Describe the working principle of diesel engine with the help if PV diagram.
7.Answer any 1 question:
a. Define lateral shift and derive an expression for it due to a parallel edged glass slab.
b.Explain the construction and working of a compound microscope with final image at near point.Also derive an expression for it's magnifying power.
8.Answer any 1 question :
a. State and explain Gauss's law of electrostatics and use it to determine the electic field intensity due to a line charge.
b.What is capacitance of a capacitor? Derive a relation for the energy stored in a capacitor when it is charged to a potential difference of V volts.
Group (C)
9.Answer any 3 questions
a. A disoriented physics professor drives 3.25 Km north, then 4.75 Km west and then
1.50 Km south. Find the magnitude and direction of resultant displacement.
b.A bob of mass 200 gram is whirled in a horizontal circle of radius 50 cm by a string inclined at 30⁰ to the vertical. Calculate the tension in the string and the speed of the bob in the horizontal circle.
c. A Copper wire and a steel wire of the same cross-sectional area and of length 1 m and 2 m respectively are connected end to end.A force is applied, which stretches their combined length by 1 cm. Find how much each wire is elongated.
d.Eight spherical raindrops of the same mass and radius are falling down with a terminal speed 5 cm/s . If they coalesce to form one big drop, what will be its terminal speed?
10.Answer any 2 questions
a.A glass flask of volume 400 cm³ is just filled with mercury at 0⁰C.How much mercury will overflow when the temperature of the system rises to 80⁰C.
b.A copper calorimeter of mass 300 gram contains 500 gram of water at temperature 15⁰C.A 560 gram block of aluminium at temperature 100⁰C is dropped in the calorimeter and the temperature is observed to increase to 25⁰C.Find the specific heat capacity of aluminum.
c.A certain volume of dry air at NTP is allowed to expand 5 times of its original volume under adiabatic condition. Calculate the final pressure and temperature.
11.A convex lens of focal length 24 cm and of refractive index 1.5 is totally immersed in water of refractive index 1.33.Find its focal length in water.
12.Three equal charges 1.8x10⁻⁶C each are located at the corners of an equilateral triangle ABC of side 10 cm.Calculate the electric potential due to these charges at the midpoint of AB.
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