Question 1:

When a beam of 10.6 eV photons of intensity 2.0 W/m² falls on a platinum surface of area 1.0×10⁻⁴ m and work function 5.6 eV, 0.53% of the incident photons eject photoelectrons. Find the number of photoelectrons emitted per second 

1) 6.25×10⁸
2) 1.25×10⁹
3) 1.25×10⁶
4) 6.25×10¹¹

Question 2:

A coil has an area of 0.05m² and it has 800 turns. It is placed perpendicular in a magnetic field of strength 4×10⁻⁵Wb/m², it is rotated through 90^o in 0.1sec. The average emf induced in the coil is

1) 0.056V
2) 0.046V
3) 0.026V
4) 0.016V

Question 3:

The electric field is 100V/m, at a distance of 20cm from the centre of a dielectric sphere of radius 10cm. Then E at 3cm distance from the centre of sphere is:

1) 100V/m
2) 125V/m
3) 120V/m
4) zero

Question 4:

A 10 µF capacitor is charged by a battery of e.m.f 100 volts. The energy stored in the capacitor is

(1) 0.5 mJ
(2) 0.05 mJ
(3) 0.05 J
(4) 0.J

Question 5:

It takes 16 min to boil some water in an electric kettle. Due to some defect it becomes necessary to remove 10% turns of the heating coil of the kettle. After repairs, how much time will it take to boil the same mass of water?

1) 17.7 min
2) 14.4 min
3) 20.9 min
4) 13.7 min

Question 6:

An electric field of intensity $$6\times 10^4 volts/m$$ is applied perpendicular to the direction of motion of the electron. A magnetic field of intensity $$8\times 10^{-2} wb/m^2$$ is applied perpendicular to both the electric field and direction of motion of the electron. What is the velocity of the electron if it passes undeflected?

1) $$7.5\times 10^5 m/s$$
2) $$7.5\times 10^{-5} m/s$$
3) $$6\times 10^4\times 8\times 10^{-2} m/s$$
4) It is never possible

Question 7:

The self inductance of a coil having 400 turns is 10 mH. The magnetic flux through the cross section of the coil corresponding to Current 2 mA is

1) 4×10⁻⁵ Wb
2) 2×10⁻³ Wb
3) 3×10⁻⁵ Wb
4) 8×10⁻³ Wb

Question 8:

The pressure exerted by an electromagnetic wave of intensity I(watt/m²)  on a non-reflecting surface is : [c is the velocity of light] 

1) I c
2) Ic²
3) I/c
4) I/c²

Question 9:

A force of 7N, making an angle q with the horizantal, acting on an object displaces it by 0.5m along the horizontal direction. If the object gains kinetic energy of 2J, what is the horizontal component of the force?

1) 2N
2) 4N.
3) 1N
4) 14N

Question 10:

Suppose you want to ride your mountain bike up a steep hill. Two paths lead to the top, one twice as long as the other. Compared to the average force exerted along the short path, F_av, the average force you exert along the longer path is:

Question 11:

 A ball is whirled around in a horizontal circle at constant speed v by a string of length r. How much work is done by the

string tension T during one complete revolution?

2. T·(2pr)

3. T·v

4. T· pr²

Question 12:

 A crate is pulled a distance d across the floor by a force F. There is a kinetic frictional force K between the crate and the floor. How much work is done on the crate by the frictional force?

1. Kd

Question 13:

 Two satellites A and B of the same mass are going around earth in concentric orbits. The distance of satellite B from Earth’s center is twice that of satellite A What is the ratio of the centripetal force acting on B to that acting on A?

1. 1/8              2. ¼

3. ½                 4. 1/Ö2

Question 14:

A particle is thrown in upward direction with Velocity Vo. It passes through a point p of height h at time t1 and t2 so t1 + t2=....

1) vo / g  2) 2vo / g  3) 2h / g   4) h / 2g

Question 15:

The half-life of $$^{215}At$$ is $$100\ mu s$$. The time taken for the radioactivity of a sample of this nucleus to decay to $$\dfrac {1}{16}th$$ of its initial value is

1) 6.3μs
2) 40μs
3) 300μs
4) 400μs

Question 16:

The electron in a hydrogen atom makes a transition n₁→n₂, where n₁ and n₂ are the principal quantum numbers of the two states. Assume the Bohr model as valid in this case. The frequency of the orbital motion of the electron in the initial state is 1 / 27 of that in the final state. The possible values of n₁ and n₂ are

1) n₁=6,n₂=3
2) n₁=4,n₂=2
3) n₁=8,n₂=1
4) n₁=3,n₂=1

Question 17:

Two small objects each with a net charge of +Q exert a force of magnitude F on each other. We replace one of the objects with another whose net charge is + 4Q. We move the +Q and +4Q charges to be 3 times as far apart as they were. What is the magnitude of the force on the +4Q charge ?

1) F
2) 4F
3) 4F/3
4) 4F/9

Question 18:

Four charges q1=1μC, q2=2μC, q3=3μC and q4=4μC are placed at (0,0,0), (1m,0,0), (0,1m,0), (0,0,1m) respectively. Let $$\vec { { F }_{ i } } $$ be the net force acting on $$i$$th charge of the given charges then $$\sum { \vec { { F }_{ i } }  } =$$

1) 0.018
2) 0.02N
3) 0.036N
4) zero

Question 19:

Suppose a tunnel is dug along the diameter of the earth. A particle is from a point distance h directly above the tunnel. The earth's density is assumed uniform and the friction is neglected. Then:

(1) The acceleration on the particle will be maximum just at the point of release.
(2) The particle will drop to the centre of the earth.
(3) The particle will have harmonic oscillation.
(4) The particle will have maximum speed when passing through the centre of the earth.

Question 20:

A man of mass 70 kg stands on a weighing scale in a lift. Which is moving upwards with a uniform acceleration of 5 m/s^-2?

The reading on the scale is

1) 35 kg

2) 70 kg

3) 105 kg

4) 120 kg

Question 21:

Under the influence of a uniform magnetic field a charged particle is moving in a circle of radius R with constant speed v. The time period of the motion

1) depends on R and not v
2) is independent of both R and v
3) depends on both R and v
4) depends on v and not on R

Question 22:

The rest mass of a deuteron is equivalent to an energy of 1876MeV, that of a proton to 939 MeV, and that of a neutron to 940 MeV. A deuteron may disintegrate to a proton and a neutron if it

1) emits an X-ray photon of energy 22 MeV
2) captures an X-ray photon of energy 22 MeV
3) emits an X-ray photon of energy 33 MeV
4) captures an X-ray photon of energy 33 MeV

Question 23:

Two charges of 50μC and 100μC1 are separated by a distance of 0.6 m0.6 m. The intensity of electric field at a point midway between them is :

1) 50 ×10⁶V/m
2) 5 ×10⁶V/m
3) 10 ×10⁶V/m
4) 10 ×10^-6V/m

Question 24:

Which of the following demonstrates that earth has a magnetic field?

(1) Earth is a planet rotating about the North-South axis.
(2) The intensity of cosmic rays (stream of charged particles coming particle coming from outer space) is more at the poles than at the Equator.
(3) A large quantity of iron-ore is found in the earth.
(4) The earth is surrounded by an ionosphere (a shell of charged particles)

Question 25:

A current of $$1/(4\pi)$$ ampere is flowing in a long straight conductor. The line integral of magnetic induction around a closed path enclosing the current carrying conductor is
1) $${10}^{-7}Wb$$ $${m}^{-1}$$
2) $$4\pi \times{10}^{-7}Wb$$ $${m}^{-1}$$
3) $$16{\pi}^{2} {10}^{-7}Wb$$ $${m}^{-1}$$
4)zero

Question 26:

Water falls from a height of 300 m assuming that the whole of the energy due to fall is converted into heat, the rise in temperature of water (J = 4.18 J/Cal) is:

1.0.54°C
2.0.62°C
3.0.82°C
4.None of the above

Question 27:

A block of ice falls from certain height and completely melts. If only 3/4th of the energy is absorbed by the block the height of fall should be

1) 48.4 m
2) 84.4m
3) 88.4m
4) 44.8m

Question 28:

A thin semi-circular ring of radius R has a positive charge q distributed uniformly over it. The net field $$\vec E$$ at the centre O is:

1) $$ \dfrac { q }{ 4{ \pi }^{ 2 }{ \varepsilon }_{ 0 }{ R }^{ 2 } } \hat { j }$$
2) $$ -\dfrac { q }{ 4{ \pi }^{ 2 }{ \varepsilon }_{ 0 }{ R }^{ 2 } } \hat { j }$$
3) $$ -\dfrac { q }{ 2{ \pi }^{ 2 }{ \varepsilon }_{ 0 }{ R }^{ 2 } } \hat { j }$$
4) $$ \dfrac { q }{ 2{ \pi }^{ 2 }{ \varepsilon }_{ 0 }{ R }^{ 2 } } \hat { j }$$

Question 29:

A hollow sphere is  held suspended, Sand is now poured it in stages, The centre of gravity of the sphere with the sand:

(1) First rises and then falls to the original position.
(2) First falls and then rises to the original position.
(3) Rises continuously
(4) Remains unchanged in the process.

Question 30:

Two slits in Young's experiment have widths in the ratio 1 : 25. The ratio of intensity at the maxima and minima in the interference pattern, $$\displaystyle \frac{I_{max}}{I_{min}}$$ is 

1) $$\displaystyle \frac{4}{9}$$
2) $$\displaystyle \frac{9}{4}$$
3) $$\displaystyle \frac{121}{49}$$
4) $$\displaystyle \frac{49}{121}$$

Question 31:

Two particles on a wave having wavelength 2m are at the distances of 5m and 9m respectively from origin. The phase difference between the particles is

1) π/2 rad
2) π rad
3) 2π rad
4) 4π rad

Question 32:

Sound waves of frequency 16 kHz are emitted by two coherent point sources placed 2 m apart at the centre of a circular train track of large radius. A person riding the train observes 2 maxima per second when the train is running at a speed of 36 km/h. Calculate the radius of the track. [Velocity of sound in air 320 m/s]

1) $$\cfrac{1000}{\pi }\ m$$
2) $$\cfrac{500}{\pi }\ m$$
3) $$\cfrac{250}{\pi }\ m$$
4) $$\cfrac{700}{\pi }\ m$$

Question 33:

A worker does 500 J of work on a 10 kg box. If the box transfers 375 J of heat to the floor through the friction between the box and the floor, what is the velocity of the box after the work has been done on it?

1) 5 m/s
2) 10 m/s.
3) 12.5 m/s
4) 50 m/s

Question 34:

A galvanometer with a coil resistance of 100 Ω gives a full scale deflection when a current of 1 mA is passed through it. The resistance of the shunt needed in ohm to convert this galvanometer into an ammeter of range 10 A is nearly

1) 0.01
2) 0.001
3) 0.1
4) 0.099

Question 35:

A metal surface of work function 1.07 eV is irradiated with light of wavelength 332 nm. The retarding potential required to stop the escape of photo electron is 

1) 4.81eV
2) 3.74eV
3) 2.65eV
4) 1.07eV

Question 36:

A rod of 10cm length is moving perpendicular to uniform magnetic field of intensity 5×10⁻⁴Wb/m². If the acceleration of the rod is 5m/s² then the rate of increase of induced emf is

1) 2.5 × 10⁻⁴Vs⁻¹
2) 25 × 10⁻⁴Vs
3) 20 × 10⁻⁴Vs
4) 20 × 10⁻⁴Vs⁻¹

Question 37:

The electric field for an electromagnetic wave in free space is $$\vec{E}=\vec{i}30\cos(kz-5\times 10^8t)$$, where magnitude of $$\vec E$$ is in $$V/m$$. The magnitude of wave vector, $$k$$ is:

1) $$0.46$$ $$rad\ m^{-1}$$
2) $$3$$ $$rad\ m^{-1}$$
3) $$1.66$$ $$rad\ m^{-1}$$
4) $$0.83$$ $$rad\ m^{-1}$$

Question 38:

The distance to which an electron of a hydrogen atom is to be removed from the atom so that the force of electrostatic attraction is equal to six times the weight of the atom, will be :

[Take g=10 m/s² and number of atoms in 1 kg1 kg of monoatomic hydrogen is 66 x 10²⁶]

1) 1.2 cm

2) 4.8 cm

3) 2.4 cm

4) 3.6 cm

Question 39:

A diving bell is to be used at great depths and so its walls are made very thick. The main reason for this is that
 
 (1) The water is much colder at great depths
 (2) Water pressure increases with depth of the water
 (3) The density of the water is much greater at great depths
 (4) Ice forms in deep water and could crush the bell

Question 40:

 Two parallel metal plates 0.04 meters apart are connected to a 1.5 volt battery. Whenfully charged, each metal plate has a charge of magnitude 9.0 x 10^-4 coulombs. What is the capacitance of the two plates?

1) 1.5 x 10^-2 F

2) 1.2 x 10^-3 F

3) 3.0 x 10^-4 F

4) 6.0 x 10^-4 F

Question 41:

Two plano-convex lenses each of focal length 10$$ { cm }$$ s refractive index $$\cfrac { 3 } { 2 }$$ are placed as shown in the figure in the space left, water $$( R I - \cfrac { 4 } { 3 } )$$ is filled.The whole arrangement is in air. The optical power of the system is (in dioptre):


1) 6.67
2) -6.67
3) 33.3
4) 20

Question 42:

In terms of Rydberg constant R, the shortest wavelength in Balmer series of hydrogen atom spectrum will have wavelength:

(1) 3/2 R
(2) 9/4 R
(3) 1/R
(4) 4/R

Question 43:

 The max. value of magnetic field in a electric field 3.2 x 10^-4 v/m (max. value) :

(1) 0.94 x 10^-14 T 
(2) 0.94 x 10¹⁰ T
(3) 1.07 x 10^-12 T
(4) 1.07x10^-9T

Question 44:

Two solid spheres of iron have their radii in the ratio 2:1 . Then ratio of the moments of inertia about their diameters is :

1) 4:1
2) 8:1
3) 16:1
4) 32:1

Question 45:

The kinetic energy of a particle in S.H.M. is 9J when it passes through the mean position. If its mass is 2 kg and the amplitude is 1m, the time period is:

1) 2.09 s
2) 3.14 s
3) 2.57 s
4) 1.79 s