## Class/Course - Engineering Entrance

### Subject - Physics

#### Total Number of Question/s - 3094

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• 1. Measurements - Quiz

1. In an experiment the angles are required to be measured using an instrument.29 divisions of the man scale exactly coincide with the 30 divisions of the vernier scale. If the smallest division of the main scale is half-a-degree (= 0.50), then the least count of the instrument is
a) One minute
b) Half minute
c) One degree
d) Half degree

2. Out of the following pairs, which one does not have identical dimensions?
a) Angular momentum and Planck constant
b) Impulse and momentum
c) Moment of inertia and moment of a force
d) Work and torque

• 2. Kinematics - Quiz

1. A particle has an initial velocity $3\hat{i} + 4\hat{j}$ and an acceleration of $0.4\hat{i} + 0.3\hat{j}$. Its speed after 10 s is
a) 10 unit
b) 7 $\sqrt{2}$ unit
c) 7 unit
d) 8.5 unit

2. If $\vec{A} \times \vec{B}$ = $\vec{B} \times \vec{A}$, then the angle between A and B is
a) π
b) π/3
c) π/2
d) π/4

• 3. Laws of Motion - Quiz

1. A mass of M kg is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of 450 with the initial vertical direction is
a) Mg (√2 + 1)
b) Mg √2
c) $\frac{Mg}{\sqrt{2}}$
d) Mg(√2-1)

2. Consider a car moving on a straight road with a speed of 100 ms-1. The distance at which car can be stopped, is [μk = 0.5]
a) 800 m
b) 1000 m
c) 100 m
d) 400 m

• 4. Work, Energy and Power - Quiz

1. A mass m moves with a velocity v and a collides inelastically with another identical mass. After collision the 1st mass moves with velocity $\frac{v}{\sqrt{3}}$ in a direction perpendicular to the initial direction of motion. Find the speed of the second mass after collision.
a) v
b) √3 v
c) $\frac{2}{\sqrt{3}}v$
d) $\frac{v}{\sqrt{3}}$

2. Statement I when ultraviolet light is incident on a photocell, its stopping potential is V0 and the maximum kinetic energy of the photoelectrons is Kmax. When the ultraviolet light is replaced by X-rays, both V0 and Kmax increase.
Statement II Photoelectrons are emitted with speeds ranging from Zero to a maximum value because of the range of frequencies present in the incident light.
a) Statement I is true, Statement II is true; Statement II is the correct explanation of Statement I.
b) Statement I is true, Statement II is true; Statement II is not the correct explanation of Statement I.
c) Statement I is false, Statement II is true.
d) Statement I is the true, Statement II is false.

• 5. Rotational Motion - Quiz

1. A body A of mass M while falling vertically downwards under gravity breaks into two parts; a body B of mass $\frac{1}{3}M$ and , body C of mass $\frac{1}{3}m$. The centre of mass of bodies B and C taken together shifts compared to that of body A towards
a) Depends on height of breaking
b) Does not shift
c) Body C
d) Body B

2. A solid sphere, hollow sphere and a ring are released from top of an inclined plane (frictionless) so that they down the plane. The maximum acceleration down the plane is for ( no rolling)
a) Solid sphere
b) Hollow sphere
c) Ring
d) All same

• 6. Gravitation - Quiz

1. A satellite of mass m revolves around the earth of radius R at a height x from its surface. If g is the acceleration due to gravity on the surface of the earth, the orbital speed of the satellite is
a) gx
b) $\frac{gR}{R - x}$
c) $\frac{gR^{2}}{R + x}$
d) $\left (\frac{gR^{2}}{R + x} \right )^{1/2}$

2. If g is the acceleration due to gravity on the earth surface, the gain in the potential energy of an object of mass m raised from the surface of the earth to a height equal to the radius R of the earth, is
a) 2 mgR
b) $\frac{1}{2}mgR$
c) $\frac{1}{4}mgR$
d) mgR

• 7. Properties of Solids and Liquids - Quiz

1. If a ball of steel (density ρ = 7.8 g cm-3) attains a terminal velocity of 10 cm-1 when falling in a tank of water (coefficient of viscosity ηwater = 8.5 x 10-4 Pa -s) then its terminal velocity in glycerine (ρ = 12 g cm-3 , η = 13.2 Pa -s) would be nearly
a) 1.6 x 10-5 cms-1
b) 6.25 x 10-4 cms-1
c) 6.45 x 10-4 cms-1
d) 1.5 x 10-5 cms-1

2. The temperature of the two outer surfaces of composite slab, consisting of two materials having coefficients of thermal conductivity K and 2 K and thickness x and 4x, respectively are T2 and T1 (T2 > T1). The rate of heat tranfer through the slab, in a steady state is $\left (\frac{A\left (T_{2} - T_{1} \right )K}{x} \right )f$ ƒ, with ƒ equals to

a) 1
b) 1/2
c) 2/3
d) 1/3

• 8. Thermodynamics - Quiz

1. During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio Cp/Cv for the gas is
a) 4/3
b) 2
c) 5/3
d) 3/2

2. A log metallic bar is carrying heat from one of its end to the order end under steady-state. The variation of temperature θ along the length x of the bar from its hot end is best described by which of the following figure.
a)
b)
c)
d)

• 9. Kinetic Theory of Gases - Quiz

1. Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperature T0, while box B contains one mole of helium at temperature (7/3) T0. The boxes are then put into thermal contact with each other, and heat flows between then until the gases reach a common final temperature (Ignore the heat capacity of boxes). Then, the final temperature of the gases, Tf, in terms of T0 is
a) Tf = $\frac{3}{7}T_{0}$
b) $\frac{7}{3}T_{0}$
c) $\frac{3}{2}T_{0}$
d) $\frac{5}{2}T_{0}$

2. A gaseous mixture consists of 16g of helium and 16g of oxygen . The ratio $\frac{C_{p}}{C_{V}}$ of the mixture
a) 1.59
b) 1.62
c) 1.4
d) 1.54

• 10. Oscillations and Waves - Quiz

1. A wave y=$\alpha sin\left ( \omega t-kx \right )$ on a string meets with another wave another wave producing a node at x=0. Then the equation of the unknown wave is
a) y=$\alpha sin\left ( \omega t+kx \right )$
b) y=$-\alpha sin\left ( \omega t+kx \right )$
c) y=$\alpha sin\left ( \omega t-kx \right )$
d) y=$-\alpha sin\left ( \omega t-kx \right )$

2. When temperature increases, the frequency of a tuning fork
a) Increases
b) Decreases
c) Remain same
d) Increases or decreases depending on the material

• 11. Electrostatics - Quiz

1. Let p(r) = $\frac{Q}{\pi R^{4}}r$ be the charge density distribution for a solid sphere of radius R and total charge Q. For a point P inside the sphere at distance r1 from the centre of the sphere the magnitude of electric field is
a) zero
b) $\frac{Q}{4\pi \epsilon_{0}r_{1}^{2}}$
c) $\frac{Qr_{1}^{2}}{4\pi \epsilon_{0}R^{4}}$
d) $\frac{Qr_{1}^{2}}{3\pi \epsilon_{0}R^{4}}$

2. A thin spherical conducting shell of radius R has a charge q. Another charge Q is placed at the centre of the shell. The electrostatic potential at a point P at a distance R/2 from the centre of the shell is
a) $\frac{2Q}{4\pi \epsilon_{0}R}$
b) $\frac{2Q}{4\pi \epsilon_{0}R}$ - $\frac{2q}{4\pi \epsilon_{0}R}$
c) $\frac{2Q}{4\pi \epsilon_{0}R}$ + $\frac{q}{4\pi \epsilon_{0}R}$
d) $\frac{\left (q + Q \right )}{4\pi \epsilon_{0}} \frac{2}{R}$

• 12. Current Electricity - Quiz

1. A rectangular loop has a sliding connector PQ of length l and resistance R Ω and it is moving with a speed v as shown. The set-up is placed in a uniform magnetic field going into the plane of the paper. The three currents I1, I2 and I are

a) $I_{1}$ = $-I_{2}$ = $\frac{Blv}{R}$, I = $\frac{Blv}{R}$
b) $I_{1}$ = $I_{2}$ = $\frac{Blv}{3R}$, I = $\frac{2Blv}{3R}$
c) $I_{1}$ = $I_{2}$ = I = $\frac{Blv}{R}$
d) $I_{1}$ = $I_{2}$ = $\frac{Blv}{6R}$, I = $\frac{Blv}{3R}$

2. If a wire is stretched to make it 0.1% longer, its resistance will
a) increase by 0.2%
b) decrease by 0.2%
c) decrease by 0.05%
d) increase by 0.05%

• 13. Magnetic Effects of Current and Magnetism - Quiz

1. A charged particle with charge q enters a region of constant, uniform and mutually orthogonal fields $\vec{E}$ and $\vec{B}$ with a velocity $\vec{v}$ perpendicular to both $\vec{E}$ and $\vec{B}$, and comes out without any change in magnitude or direction of $\vec{v}$, Then
a) $\vec{v}$ = $\vec{E} \times \frac{\vec{B}}{B^{2}}$
b) $\vec{v}$ = $\vec{B} \times \frac{\vec{E}}{B^{2}}$
c) $\vec{v}$ = $\vec{E} \times \frac{\vec{B}}{E^{2}}$
d) $\vec{v}$ = $\vec{B} \times \frac{\vec{E}}{E^{2}}$

2. The magnetic lines of force inside a bar magnetic
a) are from north-pole to south-pole of the magnet
b) do not exist
c) depend upon the area of cross-section of the bar magnet
d) are from south-pole to north-pole of the magnet

• 14. Electromagnetic Induction and Alternating Current - Quiz

1. One conducting U-tube can slide inside another as shown in figure, maintaining electrical contacts between the tubes. The magnetic field B is perpendicular to the plane of the figure. If each tube moves towards the other at a constant speed, v then the emf induced in the circuit in terms of B, l and v, where l is the width of each tube, will be

a) Blv
b) -Blv
c) zero
d) 2Blv

2. The self-inductance of the motor of an electric fan is 10H, In order to impart maximum power at 50Hz, it should be connected to a capacitance of
a) 4μF
b) 8 μF
c) 1μF
d) 2μF

• 15. Electromagnetic Waves - Quiz

1. The rms value of the electric field of the light coming from the sum is 720 NC-1. The average total energy density of the electromagnetic wave is
a) 4.58 x 10-6 Jm-3
b) 6.37 x 10-19 Jm-3
c) 81.35 x 10-12 Jm-3
d) 3.3 x 10-3 Jm-3

2. Which of the following are not electromagnetic waves?
a) Cosmic-rays
b) γ-rays
c) β-rays
d) X-rays

• 16. Optics - Quiz

1. Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm . Approximately, what is the maximum distance at which these dots can be resolved by the eye ? [Take wavelength of light = 500 nm]
a) 5 m
b) 1 m
c) 6 m
d) 3 m

2. If I0 is the intensity of the principal maximum in the single slite diffraction pattern, then what will be its intensity when the slite width is double ?
a) 2I0
b) 4I0
c) I0
d) $\frac{I_{0}}{2}$

• 17. Dual Nature of Matter and Radiation - Quiz

1. Wave property of electrons implies that they will slow diffraction effects. Davisson and Germer demonstrated this by diffracting effects .Davisson and Germer demonstrated this by diffracting electrons from crystal. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere construtively (see figure)

Electrons accelerated by potential V are diffracted from a crystal . If d = 1Å and I = 300, V should be about (h = 6.6 x 10-34 J-s, me = 9.1 x 10-31 kg, e = 1.6 x 10-19C)
a) 2000 V
b) 50V
c) 500V
d) 1000V

2. According to Einsteins photoelectric equation, the plot of the kinetic energy of the emitted photoelectrons from a metal Vs the frequency of the incident radiation gives a straight line whose slope
a) depends on the nature of the metal used
b) depends on the intensity of the radiation
c) depends both on the intensity of the radiation and the metal used
d) is the same for all metals and independent of the intensity of the radiation

• 18. Atoms and Nuclei - Quiz

1. Starting with a sample of pure $^{66}Cu$, 7/8 of it decays into Zn in 15 min. The corresponding half-life is
a) 10 min
b) 15 min
c) 5 min
d) $7\frac{1}{2}min$

2. The half-life of a radioactive substance is 20min . The approximate the interval (t2 - t1)between the time t2 when
a) 14 min
b) 20 min
c) 28 min
d) 7 min

• 19. Electronic Devices - Quiz

1. When npn transistor is used as an amplifier
a) electrons move from base to collector
b) holes move from either to base
c) electrons move from collector to base
d) holes move from base to emiiter

2. The combination of gates shown below yields

a) OR gate
b) NOT gate
c) XOR gate
d) NANAD gate

• 20. Communication Systems - Quiz

1. This question has statement 1 and statement 2. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement 1. Sky wave signals are used for long distance radio communication. These signals are in general, less stable than ground wave signals.
Statement 2 The state of ionosphere varies from hour to hour, day to day and season to season.
a) Statement 1 is true, Statement 2 is true, Statement 2 is the correct explanation of Statement 1
b) Statement 1 is true , Statement 2 is true, Statement 2 is not the correct explanations of Statement 1
c) Statement 1 is false, Statement 2 is true
d) Statement 1 is true, Statement 2 is false

2. The logic circuit shown below has the input waveforms A and B as shown. Pick out the correct output wavefrom.

a)
b)
c)
d)