Power, Power Factor & Wattless Current
A circuit has a resistance of and an impedance of . The power factor of the circuit will be
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Answer: (b)
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JEE Main · Previous year paper · Physics
These are the 72 physics questions of JEE Main 2005 (AIEEE) that are in the Physics Circle question bank, arranged chapter by chapter. Tap an option to check your answer; every question links to its full solution.
Power, Power Factor & Wattless Current
A circuit has a resistance of and an impedance of . The power factor of the circuit will be
Answer: (b)
Full solution and similar questions →Resonance, Bandwidth & Q Factor
The self inductance of the motor of an electric fan is . In order to impart maximum power at , it should be connected to a capacitance of
Answer: (d)
Full solution and similar questions →Series LCR Circuit
The phase difference between the alternating current and is Which of the following cannot be the constituent of the circuit?
Answer: (a)
Full solution and similar questions →Energy of the Electron & Energy Levels
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?

Answer: (b)
Full solution and similar questions →Combination of Capacitors
A parallel plate capacitor is made by stacking equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is then the resultant capacitance is
Answer: (b)
Full solution and similar questions →Energy Stored & Force between Plates
A fully charged capacitor has a capacitance . It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity and mass If the temperature of the block is raised by the potential difference across the capacitor is
Answer: (c)
Full solution and similar questions →Composite & Cut-Out Bodies
A T shaped object with dimensions shown in the figure, is lying on a smooth floor. A force is applied at the point parallel to such that the object has only the translational motion without rotation. Find the location of with respect to

Answer: (d)
Full solution and similar questions →Motion of Centre of Mass
A body of mass while falling vertically downwards under gravity breaks into two-parts; a body of mass and a body of mass The center of mass of bodies and taken together shifts compared to that of body towards
Answer: (a)
Full solution and similar questions →Cells: EMF, Internal Resistance & Combinations
An energy source will supply a constant current into the load if its internal resistance is
Answer: (a)
Full solution and similar questions →Cells: EMF, Internal Resistance & Combinations
Two sources of equal are connected to an external resistance The internal resistances of the two sources are and If the potential difference across the source having internal resistance is zero, then
Answer: (a)
Full solution and similar questions →Electrical Power & Heating Effect
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
Answer: (b)
Full solution and similar questions →Electrical Power & Heating Effect
The resistance of hot tungsten filament is about times the cold resistance. What will be resistance of and lamp when not in use?
Answer: (b)
Full solution and similar questions →Electrical Power & Heating Effect
Two voltmeters, one of copper and another of silver, are joined in parallel. When a total charge flows through the voltmeters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are and respectively the charge which flows through the silver voltmeter is
Answer: (a)
Full solution and similar questions →Kirchhoff's Laws & Measuring Instruments
In the circuit, the galvanometer shows zero deflection. If the batteries and have negligible internal resistance, the value of the resistor will be -

Answer: (a)
Full solution and similar questions →Kirchhoff's Laws & Measuring Instruments
A moving coil galvanometer has equal divisions. Its current sensitivity is - divisions per milliampere and voltage sensitivity is divisions per millivolt. In order that each division reads volt, the resistance in needed to be connected in series with the coil will be -
Answer: (c)
Full solution and similar questions →Potentiometer
In a potentiometer experiment the balancing with a cell is at length On shunting the cell with a resistance of the balancing length becomes . The internal resistance of the cell is
Answer: (c)
Full solution and similar questions →Matter Waves: de Broglie Wavelength
If the kinetic energy of a free electron doubles, it's deBroglie wavelength changes by the factor
Answer: (d)
Full solution and similar questions →Photoelectric Experiment: Intensity, Stopping Potential & Graphs
A photocell is illuminated by a small bright source placed away. When the same source of light is placed away, the number of electrons emitted by photo-cathode would
Answer: (a)
Full solution and similar questions →Combination of Inductors, LR & LC Circuits
A coil of inductance and resistance is connected to a source of voltage . The current reaches half of its steady state value in
Answer: (a)
Full solution and similar questions →Motional EMF
One conducting tube can slide inside another as shown in figure, maintaining electrical contacts between the tubes. The magnetic field is perpendicular to the plane of the figure. If each tube moves towards the other at a constant speed then the induced in the circuit in terms of and where is the width of each tube, will be

Answer: (c)
Full solution and similar questions →Electric Field & Field Lines
Two point charges and are located at and respectively. The location of a point on the axis at which the net electric field due to these two point charges is zero is
Answer: (b)
Full solution and similar questions →Electric Potential & Equipotentials
Two thin wire rings each having a radius are placed at a distance apart with their axes coinciding. The charges on the two rings are and The potential difference between the centres of the two rings is
Answer: (a)
Full solution and similar questions →Motion of Charges in an Electric Field
A charged ball hangs from a silk thread which makes angle with a large charged conducting sheet as shown in the figure. The surface charge density of the sheet is proportional to

Answer: (c)
Full solution and similar questions →Acceleration Due to Gravity
Average density of the earth
Answer: (d)
Full solution and similar questions →Acceleration Due to Gravity
The change in the value of at a height above the surface of the earth is the same as at a depth below the surface of earth. When both and are much smaller than the radius of earth, then which one of the following is correct?
Answer: (d)
Full solution and similar questions →Gravitational Potential & Energy
A particle of mass is kept on the surface of a uniform sphere of mass and radius Find the work to be done against the gravitational force between them to take the particle far away from the sphere (you may take )
Answer: (c)
Full solution and similar questions →Heat Conduction
The figure shows a system of two concentric spheres of radii and are kept at temperatures and , respectively. The radial rate of flow of heat in a substance between the two concentric spheres is proportional to

Answer: (d)
Full solution and similar questions →Connected Bodies & Pulleys
A block is kept on a frictionless inclined surface with angle of inclination The incline is given an acceleration to keep the block stationary. Then is equal to

Answer: (c)
Full solution and similar questions →Friction Basics
Consider a car moving on a straight road with a speed of . The distance at which car can be stopped is
Answer: (a)
Full solution and similar questions →Friction on an Incline
A smooth block is released at rest on a incline and then slides a distance . The time taken to slide is times as much to slide on rough incline than on a smooth incline. The coefficient of friction is
Answer: (b)
Full solution and similar questions →Inertia, First & Second Laws
A particle of mass 0.3 kg subjected to a force with . What will be its initial acceleration if it is released from a point 20 cm away from the origin?
Answer: (c)
Full solution and similar questions →Field of a Magnet & Magnet in a Uniform Field
A magnetic needle is kept in a non-uniform magnetic field. It experiences:
Answer: (d)
Full solution and similar questions →Elastic Potential Energy
If is stress and is young's modulus of material of a wire, the energy stored in the wire per unit volume is
Answer: (a)
Full solution and similar questions →Equations of Kinematics
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 to come to rest. If the total distance traversed is 15 S, then
Answer: (d)
Full solution and similar questions →Motion Under Gravity
A parachutist after bailing out falls without friction. When parachute opens, it decelerates at He reaches the ground with a speed of . At what height, did he bail out?
Answer: (d)
Full solution and similar questions →Velocity, Acceleration & Variable Motion
The relation between time t and distance x is t = ax2 + bx where a and b are constants. The acceleration is
Answer: (d)
Full solution and similar questions →Biot-Savart Law & Circular Coils
Two concentric coils each of radius equal to are placed at right angles to each other. ampere and ampere are the currents flowing in each coil respectively. The magnetic induction in Weber / at the center of the coils will be
Answer: (d)
Full solution and similar questions →Force on Current-Carrying Conductors
Two thin, long, parallel wires, separated by a distance carry a current of in the same direction. They will
Answer: (b)
Full solution and similar questions →Moving Charge in a Magnetic Field
A charged particle of mass and charge travels on a circular path of radius that is perpendicular to a magnetic field The time taken by the particle to complete one revolution is
Answer: (c)
Full solution and similar questions →Moving Charge in a Magnetic Field
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
Answer: (b)
Full solution and similar questions →Law of Radioactive Decay
Starting with a sample of pure of it decays into in minutes. The corresponding half life is
Answer: (d)
Full solution and similar questions →Nuclear Reactions & Q-value
A nuclear transformation is denoted by Which of the following is the nucleus of element ?
Answer: (a)
Full solution and similar questions →Nucleus: Composition, Size & Nuclear Force
If radius of the nucleus is estimated to be fermi then the radius of nucleus is estimated to be nearly
Answer: (b)
Full solution and similar questions →Radioactive Decays: Alpha, Beta, Gamma
The intensity of gamma radiation from a given source is . On passing through of lead, it is reduced to The thickness of lead which will reduce the intensity to will be
Answer: (c)
Full solution and similar questions →Periodic Motion & SHM Basics
If a simple harmonic motion is represented by its time period is
Answer: (a)
Full solution and similar questions →Periodic Motion & SHM Basics
The function represents
Answer: (a)
Full solution and similar questions →Periodic Motion & SHM Basics
Two simple harmonic motions are represented by the equations and The phase difference of the velocity of particle with respect to the velocity of particle is
Answer: (b)
Full solution and similar questions →Simple Pendulum
The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillating bob gets suddenly unplugged. During observation, till water is coming out, the time period of oscillation would
Answer: (b)
Full solution and similar questions →Comparing Two Projectiles
A projectile can have the same range for two angles of projection. If and be the times of flights in the two cases, then the product of the two time of flights is proportional to
Answer: (d)
Full solution and similar questions →Motion in a Plane (2-D Kinematics)
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
Answer: (c)
Full solution and similar questions →Spherical Surfaces & Thin Lenses
A thin glass (refractive index ) lens has optical power of in air. Its optical power in a liquid medium with refractive index will be
Answer: (b)
Full solution and similar questions →Total Internal Reflection
A fish looking up through the water sees the outside world contained in a circular horizon. If the refractive index of water is and the fish is below the surface, the radius of this circle in is
Answer: (a)
Full solution and similar questions →Moment of Inertia & Radius of Gyration
The moment of inertia of a uniform semicircular disc of mass and radius about a line perpendicular to the plane of the disc through the center is
Answer: (c)
Full solution and similar questions →Rolling Motion
An annular ring with inner and outer radii and 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, is
Answer: (c)
Full solution and similar questions →Energy Bands in Solids
The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than is incident on it. The band gap in for the semiconductor is
Answer: (d)
Full solution and similar questions →Junction Transistor
In a common base amplifier, the phase difference between the input signal voltage and output voltage is
Answer: (d)
Full solution and similar questions →Rectifiers & Filters
In a full wave rectifier circuit operating from mains frequency, the fundamental frequency in the ripple would be
Answer: (d)
Full solution and similar questions →Angle of Contact & Capillarity
A long capillary tube is dipped in water. The water rises up to If the entire arrangement is put in a freely falling elevator the length of water column in the capillary tube will be
Answer: (c)
Full solution and similar questions →Heat Engines, Refrigerators & Second Law
The temperature-entropy diagram of a reversible engine cycle is given in the figure. Its efficiency is

Answer: (d)
Full solution and similar questions →P-V Diagrams & Cyclic Processes
A system goes from to via two processes and as shown in figure. If and are the changes in internal energies in the processes and respectively, then

Answer: (b)
Full solution and similar questions →Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation
A gaseous mixture consists of of helium and of oxygen. The ratio of the mixture is
Answer: (a)
Full solution and similar questions →Units & Dimensions
Out of the following pair, which one does NOT have identical dimensions is
Answer: (c)
Full solution and similar questions →Beats
When two tuning forks (fork and fork ) are sounded simultaneously, beats per second are heated. Now, some tape is attached on the prong of the fork When the tuning forks are sounded again, beats per second are heard. If the frequency of fork is , then what was the original frequency of fork ?
Answer: (d)
Full solution and similar questions →Doppler Effect
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?
Answer: (c)
Full solution and similar questions →Diffraction at a Single Slit
If 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?
Answer: (a)
Full solution and similar questions →Polarisation
When an unpolarized light of intensity is incident on a polarizing sheet, the intensity of the light which does not get transmitted is
Answer: (b)
Full solution and similar questions →Resolving Power
Two point white dots are apart on a black paper. They are viewed by eye of pupil diameter Approximately, what is the maximum distance at which these dots can be resolved by the eye? [ Take wavelength of light ]
Answer: (b)
Full solution and similar questions →YDSE: Fringe Width & Fringe Positions
A Young's double slit experiment uses a monochromatic source. The shape of the interference fringes formed on a screen is
Answer: (d)
Full solution and similar questions →Conservation of Energy
A spherical ball of mass is stationary at the top of a hill of height . It rolls down a smooth surface to the ground, then climbs up another hill of height and finally rolls down to a horizontal base at a height of above the ground. The velocity attained by the ball is
Answer: (b)
Full solution and similar questions →Conservation of Energy
The upper half of an inclined plane with inclination 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
Answer: (d)
Full solution and similar questions →Power
A body of mass is accelerated uniformly from rest to a speed in a time The instantaneous power delivered to the body as a function of time is given by
Answer: (b)
Full solution and similar questions →Work-Energy Theorem
A bullet fired into a fixed target loses half of its velocity after penetrating How much further it will penetrate before coming to rest assuming that it faces constant resistance to motion?
Answer: (c)
Full solution and similar questions →