NSEP — National Standard Examination in Physics

A stone is dropped from the top of a tower of height H. If it takes T seconds to reach the ground, what is the position of the stone at time T/2?

• AH/4 from the top of the tower
• BH/2 from the top of the tower
• C3H/4 from the top of the tower
• DH/3 from the top of the tower

A block of mass m is placed on a smooth inclined plane of angle θ. The inclined plane is accelerated horizontally so that the block remains stationary relative to the incline. What is the magnitude of this horizontal acceleration?

• Ag tan θ
• Bg sin θ
• Cg cos θ
• Dg cot θ

A conservative force F = -kx acts on a particle. What is the work done by this force in moving the particle from x = a to x = b?

• A-0.5 * k * (b^2 - a^2)
• B0.5 * k * (b^2 - a^2)
• C-k * (b - a)
• Dk * (b - a)

The acceleration due to gravity at a height h above the Earth's surface is the same as that at a depth d below the surface. If both h and d are much smaller than the Earth's radius R, what is the relationship between h and d?

• Ad = 2h
• Bh = 2d
• Cd = h
• Dd = h/4

A wooden block floats in water with two-fifths of its volume submerged. What is the density of the wood? (Density of water = 1000 kg/m^3)

• A400 kg/m^3
• B600 kg/m^3
• C200 kg/m^3
• D800 kg/m^3

The time period of a simple pendulum is T. If the length of the pendulum is increased by 21%, what is the percentage increase in its time period?

• A10%
• B21%
• C5%
• D15%

A wire of length L and cross-sectional area A is stretched by a force F, causing an elongation l. If the wire is cut in half, what is the elongation in one of the halves under the same stretching force F?

• Al/2
• Bl
• C2l
• Dl/4

Which of the following physical quantities has the same dimensional formula as Planck's constant (h)?

• AAngular momentum
• BLinear momentum
• CWork
• DTorque

Resistance R is calculated as R = V/I. If the percentage error in voltage V is 2% and in current I is 3%, what is the maximum percentage error in the measurement of resistance R?

• A5%
• B1%
• C6%
• D1.5%

A particle moves in a straight line such that its velocity varies with displacement s as v = k * sqrt(s), where k is a positive constant. What is the acceleration of the particle?

• Ak^2 / 2
• Bk^2
• Ck^2 / 4
• Dzero

A block of mass m is pressed against a vertical wall with a horizontal force F. If the coefficient of static friction between the block and the wall is μ, what is the minimum horizontal force F required to prevent the block from sliding down?

• Amg / μ
• Bμ * mg
• Cmg
• Dmg / (1 + μ)

A car travels on a flat circular track of radius R. If the coefficient of static friction between the tires and the road is μ, what is the maximum speed the car can achieve without skidding?

• Asqrt(μ * g * R)
• Bμ * g * R
• Csqrt(g * R / μ)
• Dsqrt(μ * g / R)

A bullet of mass m penetrates a thick wooden block and loses half of its velocity after traveling a distance d. Assuming a constant resistive force from the wood, how much further will it penetrate before coming to rest?

• Ad / 3
• Bd / 2
• Cd / 4
• Dd / 9

Two particles of masses 1 kg and 3 kg are moving towards each other under mutual gravitational attraction. At a certain instant, their velocity of approach is v. What is the velocity of the center of mass of this system?

• AZero
• Bv / 4
• C3v / 4
• Dv / 2

A sphere of mass m moving with velocity v collides elastically and head-on with an identical sphere of mass m at rest. What are the velocities of the two spheres after the collision?

• AThe first sphere comes to rest; the second moves with velocity v
• BBoth spheres move with velocity v/2
• CThe first sphere moves backward with velocity -v; the second remains at rest
• DBoth spheres come to rest

A flywheel starts from rest and rotates with a constant angular acceleration of 2 rad/s^2. What is its angular displacement during the 3rd second of its motion?

• A5 rad
• B6 rad
• C9 rad
• D4 rad

The moment of inertia of a uniform circular disc of mass M and radius R about a tangent lying in its plane is:

• A5/4 * M * R^2
• B3/2 * M * R^2
• C1/2 * M * R^2
• D2 * M * R^2

A uniform ladder of length L and mass M leans against a smooth vertical wall, making an angle θ with the horizontal ground. What is the minimum coefficient of static friction μ between the ladder and the ground to prevent the ladder from slipping?

• A0.5 * cot θ
• B0.5 * tan θ
• Ccot θ
• Dtan θ

A child of mass m stands at the edge of a uniform circular rotating platform of mass M and radius R, which is rotating with an angular velocity ω0. If the child walks to the center of the platform, what is the new angular velocity of the platform? (Model the platform as a uniform disc).

• Aω0 * (1 + 2m/M)
• Bω0 * (1 + m/M)
• Cω0
• Dω0 * (1 + 4m/M)

A satellite is in a circular orbit of radius r around the Earth. If its kinetic energy is K, what is its gravitational potential energy?

• A-2K
• B-K
• C-K/2
• D2K

A block of mass m is suspended from a vertical spring of force constant k. If the block is pulled down by a distance A from its equilibrium position and released, what is its maximum speed?

• AA * sqrt(k/m)
• BA * (k/m)
• CA^2 * sqrt(k/m)
• DA * sqrt(m/k)

What is the excess pressure inside a soap bubble of radius R suspended in air? (The surface tension of the soap solution is T).

• A4T / R
• B2T / R
• CT / R
• D8T / R

A small spherical ball of radius r falls through a viscous liquid. The terminal velocity of the ball is directly proportional to:

• Ar^2
• Br
• C1 / r
• Dr^3

Water flows through a horizontal pipe of varying cross-section. At a point where the cross-sectional area is A, the velocity of flow is v. At another point where the cross-sectional area is A/2, what is the velocity of flow?

• A2v
• Bv / 2
• C4v
• Dv / 4

A projectile is launched from the bottom of an inclined plane of inclination angle β with a speed v0. If the launch angle relative to the horizontal is α (α > β), what is the condition on α to maximize the range of the projectile up the inclined plane?

• Aα = 45° + β/2
• Bα = 45° - β/2
• Cα = 45°
• Dα = β/2

A block A is connected via a light inextensible string to a movable pulley B. If block A moves horizontally with a constant acceleration a, what is the acceleration of a load attached directly to the center of the movable pulley B, assuming the other end of the string is fixed to a wall?

• Aa / 2
• Ba
• C2a
• Da / 4

A solid cylinder of mass M and radius R rolls without slipping down a rough inclined plane of inclination angle θ. What is the acceleration of the center of mass of the cylinder?

• A2/3 * g * sin θ
• B1/2 * g * sin θ
• C5/7 * g * sin θ
• Dg * sin θ

A rocket of initial mass M0 ejects exhaust gas at a constant rate r = -dM/dt with a constant exhaust velocity u relative to the rocket. If gravity is neglected, what is the velocity of the rocket when its mass has decreased to M?

• Au * ln(M0 / M)
• Bu * ln(M / M0)
• Cu * (M0 / M - 1)
• Du * (1 - M / M0)

A satellite orbits a planet in an elliptical orbit. The ratio of the maximum distance to the minimum distance of the satellite from the planet's center is 3. What is the ratio of the maximum speed to the minimum speed of the satellite?

• A3
• B9
• Csqrt(3)
• D1.5

A uniform thin rod of length L and mass M is pivoted at one of its ends so that it can swing freely in a vertical plane. What is the time period of small oscillations of this physical pendulum?

• A2π * sqrt(2L / 3g)
• B2π * sqrt(L / g)
• C2π * sqrt(L / 2g)
• D2π * sqrt(3L / 2g)

10 grams of ice at 0°C is mixed with 10 grams of water at 80°C in a calorimeter of negligible heat capacity. What is the final temperature of the mixture? (Latent heat of fusion of ice = 80 cal/g, specific heat of water = 1 cal/g°C)

• A0°C
• B40°C
• C20°C
• D10°C

A flat circular metal plate has a concentric circular hole in its center. When the plate is heated uniformly, what happens to the diameter of the hole?

• AIt increases
• BIt decreases
• CIt remains the same
• DIt decreases first and then increases

An ideal gas is maintained at a constant temperature. If its volume is doubled, what happens to its pressure?

• AIt is halved
• BIt is doubled
• CIt is quadrupled
• DIt remains unchanged

According to the kinetic theory of gases, the average translational kinetic energy of gas molecules is directly proportional to:

• AThe absolute temperature (T)
• BThe square root of absolute temperature (sqrt(T))
• CThe square of absolute temperature (T^2)
• DThe pressure of the gas (P)

The Zeroth Law of Thermodynamics establishes the basis for defining which of the following physical quantities?

• ATemperature
• BEntropy
• CInternal energy
• DWork

The rate of heat conduction through a uniform metal rod of length L and cross-sectional area A is proportional to which factor?

• AA / L
• BL / A
• CA * L
• D1 / (A * L)

In a thermodynamic process, the internal energy of a system increases by 500 J while 200 J of work is done by the system. What is the net heat added to the system during this process?

• A700 J
• B300 J
• C-300 J
• D500 J

For an ideal gas, the magnitude of the slope of an adiabatic process on a pressure-volume (P-V) diagram is how many times the slope of an isothermal process at the same point?

• Aγ
• B1 / γ
• Cγ - 1
• Dγ + 1

If the ratio of specific heats of a certain gas is γ = 1.4, which of the following is the most likely molecular structure of the gas?

• ADiatomic
• BMonatomic
• CTriatomic linear
• DPolyatomic non-linear

A gas mixture contains 2 moles of helium (monatomic, Cv = 1.5 * R) and 1 mole of hydrogen (diatomic, Cv = 2.5 * R). What is the effective molar heat capacity Cv of the mixture at constant volume?

• A11/6 * R
• B4/3 * R
• C17/6 * R
• D2 * R

An ideal gas undergoes a cyclic process represented by a circle of radius R on a P-V indicator diagram. If both axes are scaled identically, what is the work done by the gas during one complete cycle?

• Aπ * R^2
• B2 * π * R
• CZero
• D4 * π * R^2

A Carnot engine operates between a hot reservoir at 600 K and a cold reservoir at 300 K. What is the efficiency of this engine?

• A50%
• B33.3%
• C25%
• D75%

A refrigerator working between a cold reservoir at 270 K (-3°C) and a warm reservoir at 300 K (27°C) extracts 500 J of heat from the cold reservoir. What is the work input required to operate this refrigerator?

• A55.6 J
• B500 J
• C45 J
• D150 J

If the absolute temperature of a blackbody is doubled, the total rate of energy radiation increases by a factor of:

• A16
• B4
• C8
• D2

The wavelength of maximum emission intensity from a star is 500 nm. If the absolute temperature of the star is doubled, what is the new wavelength of maximum emission intensity?

• A250 nm
• B1000 nm
• C500 nm
• D125 nm

A liquid cools from 60°C to 50°C in 5 minutes when placed in a room at 30°C. Using Newton's Law of Cooling, how long will it take for the liquid to cool from 50°C to 40°C?

• A8.33 minutes
• B10 minutes
• C5 minutes
• D7.5 minutes

An ideal gas with specific heat ratio γ = 1.5 is compressed adiabatically to 1/8th of its original volume. If the initial pressure of the gas is P, what is the final pressure?

• A22.6 P
• B8 P
• C16 P
• D4 P

An ideal gas is taken through a cycle A -> B -> C -> A. A -> B is an isobaric expansion where the volume doubles, B -> C is an isochoric cooling, and C -> A is an isothermal compression returning the gas to its initial state. If the temperature at state A is T0 and the gas consists of n moles, what is the work done by the gas in the isothermal step C -> A?

• A-n * R * T0 * ln 2
• Bn * R * T0 * ln 2
• C-2 * n * R * T0 * ln 2
• D2 * n * R * T0 * ln 2