# AIIMS Year 2005 Physics Paper

Total Questions:75 Total Time: 120 Min

Remaining:

## Questions 1 of 75

Question:A projectile can have the same range R for two angles of projection. If $${{\rm{t}}_{\rm{1}}}$$ and $${{\rm{t}}_{\rm{2}}}$$ be the times of flights in the two cases, then the product of the two time of flights is proportional to

$${{\rm{R}}_{\rm{2}}}$$

$${\rm{1/}}{{\rm{R}}_{\rm{2}}}$$

1/R

R

## Questions 2 of 75

Question:An annular ring with inner and outer radii $${{\rm{R}}_1}$$ and $${{\rm{R}}_2}$$ is rolling without slipping with a uniform angular speed. The ratio of the forces experienced by the two particles situated on the inner and outer parts of the ring, $${F_1}/{F_2}$$ is

$${R_2}/{R_1}$$

$${\left( {{R_1}/{R_2}} \right)^2}$$

1

$${R_1}/{R_2}$$

## Questions 3 of 75

Question:A smooth block is released at rest on a $${\rm{45}}^\circ$$ incline and then slides a distance d. The time taken to slide is n times as much to slide on rough incline than on a smooth incline. The coefficient of friction is

$${\mu _R} = 1 - \frac{1}{{{n^2}}}$$

$${\mu _s} = \sqrt {1 - \frac{1}{{{n^2}}}}$$

$${\mu _s} = 1 - \frac{1}{{{n^2}}}$$

$${\mu _s} = \sqrt {1 - \frac{1}{{{n^2}}}}$$

## Questions 4 of 75

Question:The upper half of an inclined plane with inclination $$\phi$$ is perfectly smooth while the lower half is rough. A body starting from rest at the top will again come to rest at the bottom if the coefficient of friction for the lower half is given by

2sin$$\phi$$

2cos$$\phi$$

2tan$$\phi$$

tan$$\phi$$

## Questions 5 of 75

Question:A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further it will penetrate before coming to rest assuming that it faces constant resistance to motion?

3.0 cm

2.0 cm

1.5 cm

1.0 cm

## Questions 6 of 75

Question:Out of the following pair, which one does NOT have identical dimensions is

angular momentum and Planck's constant

impulse and momentum

moment of inertia and moment of a force

work and torque

## Questions 7 of 75

Question:The relation between time t and distance x is $${\rm{t}} = {\rm{a}}{{\rm{x}}^{\rm{2}}} + {\rm{bx}}$$ where a and b are constants. The acceleration is

$$- {\rm{2ab}}{{\rm{v}}^{\rm{2}}}$$

$${\rm{2b}}{{\rm{v}}^{\rm{3}}}$$

$$- {\rm{2a}}{{\rm{v}}^{\rm{3}}}$$

$${\rm{2a}}{{\rm{v}}^{\rm{2}}}$$

## Questions 8 of 75

Question:A car starting from rest accelerates at the rate f through a distance S, then continues at constant speed for time t and then decelerates at the rate f/2 to come to rest. If the total distance traversed is 15 S, then

S=ft

S = 1/6 $${\rm{f}}{{\rm{t}}^{\rm{2}}}$$

S = 1/2

S = 1/4 $${\rm{f}}{{\rm{t}}^{\rm{2}}}$$

None of these

## Questions 9 of 75

Question:A particle is moving eastwards with a velocity of 5 m/s in 10 seconds the velocity changes to 5 m/s northwards. The average acceleration in this time is

$$\frac{1}{{\sqrt 2 }}m/{s^2}$$ towards north-east

$$\frac{1}{2}m/{s^2}$$ towards north.

zero

$$\frac{1}{{\sqrt 2 }}m/{s^2}$$towards north-west

## Questions 10 of 75

Question:A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at 2 m/s$$^{\rm{2}}$$. He reaches the ground with a speed of 3 m/s. At what height, did he bail out?

91 m

182 m

293 m

111 m

## Questions 11 of 75

Question:A block is kept on a frictionless inclined surface with angle of inclination $$\alpha$$. The incline is given an acceleration a to keep the block stationary. Then a is equal to

g/tan $$\alpha$$

g cosec $$\alpha$$

g

g tan $$\alpha$$

## Questions 12 of 75

Question:A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is

40 m/s

20 m/s

10 m/s

10$$\sqrt {30}$$ m/s

## Questions 13 of 75

Question:A body A of mass M while falling vertically downwards under gravity breaks into two parts; a body B of mass 1/3 M and a body C of mass 2/3 M. The centre of mass of bodies B and C taken together shifts compared to that of body A towards

depends on height of breaking

does not shift

body C

body B

## Questions 14 of 75

Question:The moment of inertia of a uniform semicircular disc of mass M and radius r about a line perpendicular to the plane of the disc through the centre is

$$\frac{1}{4}M{r^2}$$

$$\frac{2}{5}M{r^2}$$

$$M{r^2}$$

$$\frac{1}{2}M{r^2}$$

## Questions 15 of 75

Question:A particle of mass 0.3 kg is subjected to a force F=?kx with k=15 N/m. What will be its initial acceleration if it is released from a point 20 cm away from the origin?

$${\rm{3 m}}/{{\rm{s}}^{\rm{2}}}$$

$${\rm{15 m}}/{{\rm{s}}^{\rm{2}}}$$

$${\rm{5 m}}/{{\rm{s}}^{\rm{2}}}$$

$${\rm{1}}0{\rm{ m}}/{{\rm{s}}^{\rm{2}}}$$

## Questions 16 of 75

Question:The block of mass M moving on the frictionless horizontal surface collides with a spring of spring constant K and compresses it by length L. The maximum momentum of the block after collision is

$$\sqrt {MK} L$$

$$\frac{{K{L^2}}}{{2M}}$$

Zero

$$\frac{{M{L^2}}}{K}$$

## Questions 17 of 75

Question:A mass 'm' moves with a velocity v and collides inelastically with another identical mass. After collision the 1st mass moves with velocity $$v/\sqrt 3$$ in a direction perpendicular to the initial direction of motion. Find the speed of the $${{\rm{2}}^{{\rm{nd}}}}$$ mass after collision v

$$\sqrt 3$$

v

$$2v/\sqrt 3$$

$$v/\sqrt 3$$

## Questions 18 of 75

Question:A 20 cm long capillary tube is dipped in water. The water rises up to 8 cm. If the entire arrangement is put in a freely falling elevator the length of water column in the capillary tube will be

8 cm

10 cm

4 cm

20 cm

## Questions 19 of 75

Question:If S is stress and Y is Young's modulus of material of a wire, the energy stored in the wire per unit volume is

$${\rm{2}}{{\rm{S}}^{\rm{2}}}{\rm{Y}}$$

$${{\rm{S}}^{\rm{2}}}/{\rm{2Y}}$$

$${\rm{2Y}}/{{\rm{S}}^{\rm{2}}}$$

S/2Y

## Questions 20 of 75

Question:Average density of the earth

does not depend on g

is a complex function of g

is directly proportional to g

is inversely proportional to g

## Questions 21 of 75

Question:A body of mass m is accelerated uniformly from rest to a speed v in a time T. The instantaneous power delivered to the body as a function time is given by

$$\frac{{m{v^2}}}{{{T^2}}}.t$$

$$\frac{{m{v^2}}}{{{T^2}}}.{t^2}$$

$$\frac{1}{2}\frac{{m{v^2}}}{{{T^2}}}.t$$

$$\frac{1}{2}\frac{{m{v^2}}}{{{T^2}}}.{t^2}$$

## Questions 22 of 75

Question:Consider a car moving on a straight road with a speed of 100 m/s. The distance at which car can be stopped is $$[{\mu _{\rm{k}}} = 0.{\rm{5}}]$$

800 m

1000 m

100 m

400 m

## Questions 23 of 75

Question:Which of the following is incorrect regarding the first law of thermodynamics?

It is not applicable to any cyclic process

It is a restatement of the principle of conservation of energy

It introduces the concept of the internal energy

It introduces the concept of the entropy

None of these

## Questions 24 of 75

Question:A 'T' shaped object with dimensions shown in the figure, is lying on a smooth floor. A force F is applied at the point P parallel to AB, such that the object has only the translational motion without rotation. Find the location of P with respect to C

$$\frac{2}{3}l$$

$$\frac{3}{2}l$$

$$\frac{4}{3}l$$

$$l$$

## Questions 25 of 75

Question:The change in the value of g at a height 'h' above the surface of the earth is the same as at a depth 'd' below the surface of earth. When both 'd' and 'h'are much smaller than the radius of earth, then which one of the following is correct?

$$d = \frac{h}{2}$$

$$d = \frac{{3h}}{2}$$

$$d = 2h$$

$$d = h$$

## Questions 26 of 75

Question:A particle of mass 10 g is kept on the surface of a uniform sphere of mass 100 kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere (you may take $${\rm{G }} = {\rm{ 6}}.{\rm{67}} \times {\rm{1}}{0^{ - {\rm{11}}}}{\rm{N}}{{\rm{m}}^{\rm{2}}}/{\rm{k}}{{\rm{g}}^{\rm{2}}}$$)

$${\rm{13}}.{\rm{34}} \times {\rm{1}}{0^{ - {\rm{1}}0}}{\rm{J}}$$

$${\rm{3}}.{\rm{33}} \times {\rm{1}}{0^{ - {\rm{1}}0}}{\rm{J}}$$

$${\rm{6}}.{\rm{67}} \times {\rm{1}}{0^{ - {\rm{9}}}}{\rm{J}}$$

$${\rm{6}}.{\rm{67}} \times {\rm{1}}{0^{ - {\rm{1}}0}}{\rm{J}}$$

## Questions 27 of 75

Question:A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio $$\frac{{{C_p}}}{{{C_v}}}$$ of the mixture is

1.59

1.62

1.4

1.54

## Questions 28 of 75

Question:The intensity of gamma radiation from a given source is I. On passing through 36mm of lead, it is reduced to $$\frac{{\rm{I}}}{8}$$. The thickness of lead which will reduce the intensity to $$\frac{{\rm{I}}}{2}$$ will be

6 mm

9 mm

18 mm

12 mm

## Questions 29 of 75

Question:The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than 2480 nm is incident on it. The band gap in (eV) for the semiconductor is

1.1 eV

2.5 eV

0.5 eV

0.7 eV

## Questions 30 of 75

Question:A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed $$\frac{1}{2}$$ m away, the number of electrons emitted by photo cathode would

decrease by a factor of 4

increase by a factor of 4

decrease by a factor of 2

increase by a factor of 2

## Questions 31 of 75

Question:Starting with a sample of pure $$^{{\rm{66}}}{\rm{Cu}},$$ 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is

10

minutes

15 minutes

5 minutes

## Questions 32 of 75

Question:$$7{\textstyle{1 \over 2}}$$ minutesIf radius of $${}_{13}^{27}Al$$nucleus is estimated to be 3.6 Fermi then the radius $${}_{52}^{125}Te$$ nucleus be nearly

6 fermi

8 fermi

4 fermi

5 fermi

## Questions 33 of 75

Question:The temperature-entropy diagram of a reversible engine cycle is given in the figure. Its efficiency is

1/2

1/4

1/3

2/3

## Questions 34 of 75

Question:The figure shows a system of two concentric spheres of radii $${r_1}$$ and $${r_2}$$ and kept at temperatures $${T_1}$$ and $${T_2}$$ respectively. The radial rate of flow of heat in a substance between the two concentric sphere is proportional to

$$\frac{{{r_1} - {r_2}}}{{{r_1}{r_2}}}$$

$$\ln \left( {\frac{{{r_2}}}{{{r_1}}}} \right)$$

$$\frac{{{r_1}{r_2}}}{{{r_2} - {r_1}}}$$

$$\ln \left( {{r_2} - {r_1}} \right)$$

## Questions 35 of 75

Question:A system goes from A to B via two processes I and II as shown in the figure. If $$\Delta {{\rm{U}}_{\rm{1}}}$$ and $$\Delta {{\rm{U}}_{\rm{2}}}$$ are the changes in internal energies in the processes I and II respectively, the

$$\Delta {{\rm{U}}_{\rm{1}}} = \Delta {{\rm{U}}_{\rm{2}}}$$

relation between $$\Delta {{\rm{U}}_{\rm{1}}}$$and $$\Delta {{\rm{U}}_{\rm{2}}}$$ can not be determined

$$\Delta {{\rm{U}}_{\rm{2}}} > \Delta {{\rm{U}}_{\rm{1}}}$$

$$\Delta {{\rm{U}}_{\rm{2}}} < \Delta {{\rm{U}}_{\rm{1}}}$$

## Questions 36 of 75

Question:The function $${\rm{si}}{{\rm{n}}^{\rm{2}}}(\omega {\rm{t}})$$ represents

a periodic, but not simple harmonic motion with a period $${\rm{2}}\pi /\omega$$

a periodic, but not simple harmonic motion with a period $$\pi /\omega$$

a simple harmonic motion with a period $${\rm{2}}\pi /\omega$$

a simple harmonic motion with a period $$\pi /\omega$$

## Questions 37 of 75

Question:A Young's double slit experiment uses a monochromatic source. The shape of the interference fringes formed on a screen is

hyperbola

Circle

straight line

parabola

## Questions 38 of 75

Question:Two simple harmonic motions are represented by the equation $${y_1} = 0.1\,\,\,\sin \left( {100\pi t + \frac{\pi }{3}} \right)$$ and $${y_2} = 0.1\,\cos \pi t$$. The phase difference of the velocity of particle 1 w.r.t. the velocity of the particle 2 is

$$- \pi /{\rm{6}}$$

$$\pi /{\rm{3}}$$

$$- \pi /{\rm{3}}$$

$$\pi /6$$

## Questions 39 of 75

Question:A fish looking up through the water sees the outside world contained in a circular horizon. If the refractive index of water is 4/3 and the fish is 12 cm below the surface, the radius of this circle in cm is

36$$\sqrt 7$$

36$$\sqrt 7$$

36$$\sqrt 5$$

4$$\sqrt 5$$

## Questions 40 of 75

Question: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]

5 m

1m

6 m

3m

## Questions 41 of 75

Question:A thin glass (refractive index 1.5) lens has optical power of -5D in air. Its optical power in a liquid medium with refractive index 1.6 will be

1 D

-1D

25 D

-25 D

None of these

## Questions 42 of 75

Question:The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy ?

III

IV

I

II

## Questions 43 of 75

Question:If the kinetic energy of a free electron doubles. Its deBroglie wavelength changes by the factor

$$\frac{1}{2}$$

2

$$\frac{1}{{\sqrt 2 }}$$

$$\sqrt 2$$

## Questions 44 of 75

Question:In a common base amplifier, the phase difference between the input signal voltage and output voltage is

$$\frac{\pi }{4}$$

$$\pi$$

0

$$\frac{\pi }{2}$$

## Questions 45 of 75

Question:In a full wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be

50 Hz

25 Hz

100 Hz

70.7 Hz

## Questions 46 of 75

Question:A nuclear transformation is denoted by $${\rm{X(n,}}\alpha {\rm{)}}\,\,{}_3^7Li$$. Which of the following is the nucleus of element X ?

$${}_{}^{12}{C_6}$$

$${}_5^{10}B$$

$${}_5^9B$$

$${}_4^{11}Be$$

## Questions 47 of 75

Question:A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 volt, the resistance in ohms needed to be connected in series with the coil will be

$${\rm{1}}{0^{\rm{3}}}$$

$${\rm{1}}{0^5}$$

99995

9995

## Questions 48 of 75

Question:Two voltameters one of copper and another of silver, are joined in parallel. When a total charge q flows through the voltameters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are $${{\rm{z}}_{\rm{1}}}$$ and $${{\rm{z}}_{\rm{2}}}$$ respectively the charge which flows through the silver voltameter is

$$\frac{q}{{1 + {\textstyle{{{z_1}} \over {{z_2}}}}}}$$

$$\frac{q}{{1 + {\textstyle{{{z_2}} \over {{z_1}}}}}}$$

$$q{\textstyle{{{z_2}} \over {{z_1}}}}$$

$$q{\textstyle{{{z_1}} \over {{z_2}}}}$$

## Questions 49 of 75

Question:In the circuit, the galvanometer G shows zero deflection. If the batteries A and B have negligible internal resistance, the value of the resistor R will be

200 $$\Omega$$

100 $$\Omega$$

500 $$\Omega$$

1000 $$\Omega$$

## Questions 50 of 75

Question:Two sources of equal emf are connected to an external resistance R. The internal resistance of the two sources are $${{\rm{R}}_{\rm{1}}}$$ and $${{\rm{R}}_{\rm{2}}}$$($${{\rm{R}}_{\rm{2}}}$$ > $${{\rm{R}}_{\rm{1}}}$$). If the potential difference across the source having internal resistance $${{\rm{R}}_{\rm{2}}}$$ is zero, then

$${\rm{R }} = {\rm{ }}{{\rm{R}}_{\rm{2}}} \times ({{\rm{R}}_{\rm{1}}} + {\rm{ }}{{\rm{R}}_{\rm{2}}})/{{\rm{R}}_{\rm{2}}}--{\rm{ }}{{\rm{R}}_{\rm{1}}})$$

R = $${{\rm{R}}_{\rm{2}}}$$ x $${{\rm{R}}_{\rm{1}}}$$

R = $${{\rm{R}}_{\rm{1}}}$$$${{\rm{R}}_{\rm{2}}}$$ / ($${{\rm{R}}_{\rm{1}}}$$ + $${{\rm{R}}_{\rm{2}}}$$)

R = $${{\rm{R}}_{\rm{1}}}$$$${{\rm{R}}_{\rm{2}}}$$ / ($${{\rm{R}}_{\rm{2}}}$$- $${{\rm{R}}_{\rm{1}}}$$)

## Questions 51 of 75

Question:A fully charged capacitor has a capacitance 'C' it is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity 's' and mass 'm'. If the temperature of the block is raised by '$$\Delta {\rm{T}}$$'. The potential difference V across the capacitance is

$$\sqrt {\frac{{2mC\Delta T}}{s}}$$

$$\frac{{mC\Delta T}}{s}$$

$$\frac{{ms\Delta T}}{C}$$

$$\sqrt {\frac{{2ms\Delta T}}{C}}$$

## Questions 52 of 75

Question: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

BlV

Â -BlV

zero

2 BlV

## Questions 53 of 75

Question:A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

doubled

four times

one fourth

halved

## Questions 54 of 75

Question:Two thin, long parallel wires separated by a distance 'd' carry a current of 'i' A in the same direction. They will

attract each other with a force of $${\mu _0}{{\rm{i}}^{\rm{2}}}/({\rm{2}}\pi {\rm{d}})$$

repel each other with a force of $${\mu _0}{{\rm{i}}^{\rm{2}}}/{\rm{ }}({\rm{2}}\pi {\rm{d}})$$

attract each other with a force of $${\mu _0}{{\rm{i}}^{\rm{2}}}({\rm{2}}\pi {{\rm{d}}^{\rm{2}}})$$

repel each other with a force of $${\mu _0}{{\rm{i}}^{\rm{2}}}({\rm{2}}\pi {{\rm{d}}^{\rm{2}}})$$

## Questions 55 of 75

Question:A charged ball B hangs from a silk thread S which makes an angle $$\theta$$ with a large charged conducting sheet P, as show in the figure. The surface charge density $$\sigma$$ of the sheet is proportional to

cos $$\theta$$

cot $$\theta$$

sin $$\theta$$

tan $$\theta$$

## Questions 56 of 75

Question:Two point charges + 8q and -2q are located at x = 0 and x = L respectively. The location of a point on the x axis at which the net electric field due to these two point charges is zero is

2L

L/4

8L

4L

## Questions 57 of 75

Question:Two thin wires rings each having a radius R are placed at a distance d apart with their axes coinciding. The charges on the two rings are +q and -q. The potential difference between the centres of the two rings is

$$QR/4\pi {\varepsilon _0}{d^2}$$

$$\frac{Q}{{2\pi {\varepsilon _0}}}\left[ {\frac{1}{R} - \frac{1}{{\sqrt {{R^2} + {d^2}} }}} \right]$$

Zero

$$\frac{Q}{{4\pi {\varepsilon _0}}}\left[ {\frac{1}{R} - \frac{1}{{\sqrt {{R^2} + {d^2}} }}} \right]$$

## Questions 58 of 75

Question:A parallel plate capacitor is made by stacking n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is C then the resultant capacitance is

(n-1)C

(n+1)C

C

nC

## Questions 59 of 75

Question:When two tuning forks (fork 1 and fork 2) are sounded simultaneously, 4 beats per second are heard. Now, some tape is attached on the prong of the fork 2. When the tuning forks are sounded again, 6 beats per seconds are heard. If the frequency of fork 1 is 200 Hz, then what was the original frequency of fork 2?

200 Hz

202 Hz

196 Hz

204 Hz

## Questions 60 of 75

Question:If a simple harmonic motion is represented by

$$\frac{{{\rm{2}}\pi }}{\alpha }$$

$${\rm{2}}\pi$$

$${\rm{2}}\pi \alpha$$

$${\rm{2}}\pi \sqrt \alpha$$

## Questions 61 of 75

Question:The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillation bob gets suddenly unplugged. During observation, till water is coming out, the time period of oscillation would

first increase and then decrease to the original value.

first decreased then increase to the original value.

remain unchanged.

increase towards a saturation value.

## Questions 62 of 75

Question:An observer moves towards a stationary source of sound, with a velocity one fifth of the velocity of sound. What is the percentage increase in the apparent frequency?

zero

0.50%

5%

20%

## Questions 63 of 75

Question:If $${{\rm{I}}_0}$$ is the intensity of the principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled?

2$${{\rm{I}}_0}$$

4$${{\rm{I}}_0}$$

$${{\rm{I}}_0}$$

$${{\rm{I}}_0}$$/2

## Questions 64 of 75

Question:Two concentric coils each of radius equal to $${\rm{2}}\pi$$ cm are placed at right angles to each other. 3 Ampere and 4 ampere are the currents flowing in each coil respectively. The magnetic induction in Weber/m$$^2$$ at the centre of the coils will be $$(\mu 0 = {\rm{ 4}}\pi {\rm{ }} \times {\rm{1}}{0^{ - {\rm{7}}}}{\rm{Wb}}/{\rm{A}} - {\rm{m}})$$

12 x $${\rm{1}}{0^{ - {\rm{5}}}}$$

$${\rm{1}}{0^{ - {\rm{5}}}}$$

5 x $${\rm{1}}{0^{ - {\rm{5}}}}$$

7 x $${\rm{1}}{0^{ - {\rm{5}}}}$$

## Questions 65 of 75

Question:A coil of inductance 300 mH and resistance 2? is connected to a source of voltage 2V. The current reaches half of its steady state value in

0.05s

0.1s

0.15s

0.3s

## Questions 66 of 75

Question:The self inductance of the motor of an electric fan is 10 H. In order to impart maximum power at 50 Hz, it should be connected to a capacitance of

$${\rm{4}}\mu {\rm{F}}$$

$${\rm{8}}\mu {\rm{F}}$$

$${\rm{1}}\mu {\rm{F}}$$

$${\rm{2}}\mu {\rm{F}}$$

## Questions 67 of 75

Question:An energy source will supply a constant current into the load of its internal resistance is

equal to the resistance of the load.

very large as compared to the load resistance.

zero

non-zero but less than the resistance of the load.

## Questions 68 of 75

Question:A circuit has a resistance of 12$$\Omega$$ and an impedance of 15$$\Omega$$. The power factor of the circuit will be

0.8

0.4

1.25

0.125

## Questions 69 of 75

Question:The phase difference between the alternating current and emf is $$\pi /{\rm{2}}$$ . Which of the following cannot be the constituent of the circuit?

C alone

R.L

L.C.

L alone

## Questions 70 of 75

Question:A uniform electric field and a uniform magnetic field are acting along the same direction in a certain region. If an electron is projected along the direction of the fields with a certain velocity then

its velocity will decrease.

its velocity will increase.

it will turn towards right of direction of motion.

it will turn towards left of direction of motion.

## Questions 71 of 75

Question:A charged particle of mass m and charge q travels on a circular path of radius r that is perpendicular to a magnetic field B. The time taken by the particle to complete one revolution is

$$\frac{{2\pi mq}}{B}$$

$$\frac{{2\pi {q^2}B}}{m}$$

$$\frac{{2\pi qB}}{m}$$

$$\frac{{2\pi m}}{{qB}}$$

## Questions 72 of 75

Question:In a potentiometer experiment the balancing with a cell is at length 240 cm. On shunting the cell with a resistance of $${\rm{2}}\Omega$$ the balancing length becomes 120 cm. The internal resistance of the cell is

$${\rm{1}}\Omega$$

$$0.{\rm{5}}\Omega$$

$${\rm{4}}\Omega$$

$${\rm{2}}\Omega$$

## Questions 73 of 75

Question:The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use?

$${\rm{4}}0\Omega$$

$${\rm{2}}0\Omega$$

$${\rm{4}}00\Omega$$

$${\rm{2}}00\Omega$$

## Questions 74 of 75

Question:A magnetic needle is kept in a non-uniform magnetic field. It experiences

a torque but not a force

neither a force nor a torque

a force and a torque.

a force but not a torque.

## Questions 75 of 75

Question:When an unpolarized light of intensity $${{\rm{I}}_0}$$ is incident on a polarizing sheet, the intensity of the light which does not get transmitted is

$$\frac{1}{2}{I_0}$$
$$\frac{1}{4}{I_0}$$
$${l_1}$$