Start Test

A coil of 50 turns has dimension 10 x 10 cm. It is roated at the rate of 5 rps in a uniform magnetic field of flux density 0.7T. The maximum emf included in it is

The coils in two moving coil galvanometer have their areas in the ratio of 2:3 and number of turns in the ratio 4:5. These two coils carry the same current and are situated in the same field. The deflections produced by these coil will be in the ratio of

Which of the following statements is not true in the case of 1 Huygen's eye piece

A Tuning fork A produces 6 beats per second with another fork B.On loading B with a little wax,it produces 5 beats per second with A if the frequency of A is 256Hz,the frequency of B is

Eight spherical rain drops of the same mass and radius are falling down with a terminal speed of 6 cm-s-1. If they coalesce to form one big drop, what will be the terminal speed of bigger drop (Neglect the buoyancy of the air)

A wire carrying a current of 4A is in the form of a circle it is necessary to have a magnetic field of induction πx10-5T at the center.The radius of the circle must be

The refractive index of the material of a double convex lens is 1.5 and its focal length is 5 cm. If the radii of curvature are equal, the value of the radius of curvature (in cm) is

A wave of frequency 500Hz has a velocity of 360ms-1,what is the distance between two nearest points 600 out of phase?

The equation of wave is y=10 cos2π(t/0.02-x/10),where ‘t’ is in seconds an x in cm.The phase difference between two points separated by a distance of 5 cm at any instant is

In an experiment on photoelectric emission from a metallic surface, wavelength of incident light is 2xl0-7 m and stopping potential is 2.5 V. The threshold frequency of the metal (in Hz) approximately (charge of electron e= 1.6 x 10-19 C Planck's constant h = 6.67 x 10-34 J-s)

A motor car approaching a cliff with a velocity of 90 kmph sounds the horn and the echo is heard after 20 seconds.Assuming the velocity of sound in air to be 332m/s,the distance between the car and cliff when the horn is sounded is

In a thermo couple the cold junction is at 300C.The temperature of inversion is found to be 5400C,Then the neutral temperature is

At least how many thermal neutrons should be available to start a fission reaction

In a photoelectric cell, wavelength of the incident light is changed from 4000A0 to 3600A0. Change in stopping potential will be nearly

If 9.8 gms of H2SO4 is neutralized exactly with strong alkali ,the heat evolved is(?H of neutralization is 13.6 K.cal)

A bullet of mass 10 g is fired horizontally with a velocity 1000ms-1 from a rifle situated at a height 50 m above the ground. If the bullet reaches the ground with a velocity 500ms-1, the work done against air resistance in the trajectory of the bullet is : (g=10ms-2)

One junction of thermo couple is at 00C and the other junction is heated .Maximum current in the thermo couple is observed when hot junction is at 2400C.The temperature of the hot junction at which the direction of current reverses is

An ideal gas at a pressure of 1 atm and temperature of 270C is compressed adiabatically until its pressure becomes 8 times the initial pressure, then final temperature is : (γ = 3/2)

Thomson coefficient of a conductor is 10μVK. The two ends of it are kept at 500 C and 600 C respectively. Amount of heat absorbed by the conductor when a charge of 10 C flows through it, is:

The frequency of a tuning fork x is 5% greater than that of a standard fork of frequency K. The frequency of another fork y is 3% less than of K. When x and y are vibrated together 4 beats per second. The frequencies of x and y are

The equation of trajectory of a projectile is y = 10x - (5/9) x2. If we assume g =10 ms-2, the range of projectile (in meter) is

An n-p-n transistor power amplifier in C-E configuration gives :

A force is experienced by cathode rays when they pass through uniform electric field

Work done by 0.1 mole of gas at 270C when it expands to double its volume at constant pressure is : (assume R = 2 cal/mol-1 K-1)

A motor of power P0 is used to deliver water at a certain rate through a given horizontal pipe. To increase the rate of flow of water through the same pipe n times, the power of the motor is increased to P1 The ratio of P1 to P0 is

Two strings A and B of lengths. LA = 80 cm and LB = x cm respectively are used separately in a sonometer. The ratio of their densities {dA/dB) is 0.81. The diameter of B is one-half that of A. If the strings have the same tension and fundamental frequency the value of x is :

If a body is in equilibrium under a set of non-collinear forces, the minimum number of forces has to be

A train approaching a level crossing at a speed of 20m/s sounds a horn of frequency 628Hz when 80m form the crossing.A person is standing at 60m from the level crossing on a road which is perpendicular to the railway track.Then the apparent frequency heard by the person is (velocity of sound in air is 330m/s)

The distances between the objective and the eye lens of an astronomical telescope when adjusted for parallel light is 100cm.The measured value of the magnification is 19.The focal length of objective and eye piece are

The two surfaces of a biconvex lens has same radii of curvatures. This lens is made of glass of refractive index 1.5 and has a focal length 10 cm in air. The lens is cut into two equal halves along a plane perpendicular to its principal axis to yield two plano-convex lenses. The two pieces are glued such that the convex surfaces touch each other. If this combination lens is immersed in water (refractive index = 4/3), its focal length (in cm) is :

A source of sound is approaching a stationary observer with a velocity 1/10th of the velocity of sound in air so that apparent decrease in the wavelength of sound waves is 10cm.If the observer is approaching the same source of sound at rest with a velocity 1/5th of velocity of sound in air,the apparent increase in the frequency of sound is(velocity of sound in air=340m/s)

The frequency of a stretched uniform wire under tension is in resonance with the fundamental frequency of a closed tube.If the tension in the wire is increased by 8N, it is in resonance with first overtone of the closed tube.The initial tension in the wire is

If the cold junction is held at 00C, the same thermo emf V of a thermocouple varies as V = 10 x 10 6t - * x 10 bt2, where t is the 40 temperature of the hot junction in 0C. The neutral temperature and the maximum value of thermo emf are respectively:

An iron block of sides 50 cm x 8 cm x 15 cm has to be pushed along the floor. The force required will be minimum when the surface in contact with ground is:

A fork gives 5beats/sec with a 40cm long sonometer wire.If the length of the wire is shortened by 1 cm,the number of beats/sec is still the same.The frequency of the fork is

A magnetic needle lying parallel to a magnetic field is turned through 600.The work does on it is w. The torque required to maintain the magnetic needle in the position mentioned above is

An open pipe resonates with a tuning fork of frequency 500Hz.It is observed that two successive notes are formed at distances 16cm and 46 cm from the open end .the speed of sound in air in the pipe is

When an unknown resistance and a resistance of 4 ? are connected in the left and right gaps of a meterbridge, The balance point is obtained at 50 cm. The shift in the balance point if a 4 ? resistance is now connected in parallel to the resistance in the right gap is

A cell of emf 2V and negligible resistance is connected in series with a resistance of 5 ohm,and a potentiometer wire of resistance 10 ohm.what is the potential drop per cm if the length of the potentiometer wire is 10m.The emf of a cell which is balanced by 750cm long wire is

If the angle of minimum deviation produced by an equilateral prosm is 300, the refractive index of material of prism is

Two lenses of focal lengths +10cm, and -15cm when put in contact behave like a convex lens .They will have zero longitudinal chromatic aberration if their dispersive powers are in the ratio

The radii and Young's moduli of two uniform wires A and B are in the ratio 2 : 1 and 1 : 2 respectively. Both wires are subjected to the same longitudinal force. If the increase in length of the wire A is one percent the percentage increase in length of the wire B is

Two soap bubbles combine to form a single bubble. In this process, the change in volume and surface area are respectively V and A. If P is the atmospheric pressure, and T is the surface tension of the soap solution, the following relation is true .

A bar magnet of 10 cm long is kept with its north (N)-pole pointing North. A neutral point is formed at a distance of 15 cm from each pole. Given the horizontal component of earth's field is 0.4 Gauss, the pole strength of the magnet is

The temperature of a thin uniform circular disc, of one metre diameter is increased by 100C. The percentage increase in moment of inertia of the disc about an axis passing through its centre and perpendicular to the circular face : (linear coefficient of expansion = 11 x l0-6/ 0C )

The angle of minimum deviation when light is incident at an angle of 450 on the refracting faces of an equilateral prism of refractive index 1.414 is

A body is projected vertically upwards from the surface of the earth with a velocity equal to half the escape velocity. If R is the radius of the earth, maximum height attained by the body from the surface of the earth is

Frequency of tuning fork A is 250 Hz. It produces 4 beats/sec with another tuning fork B. When A is filed, the beat frequency is 6 beats/sec. The frequency of B is

The waves are represented by the following equations y1=5 sin 2π(10t-0.1x),y2=10 sin 2π(20t-0.2x)ratio of intensities l2/l1 will be

A steady current is set up in a metallic wire of non-uniform cross-section. Then the drift velocity related the area of cross-section (A) as

A coil has 1,000 turns and 500cm2 as its area.The plane of the coil is placed at right angles to a magnetic induction field of 2x10-5web/m2.The coil is rotated through 1800 in 0.2 seconds.The average emf induced in the coil,in milli volts,is

A sound wave passing through an ideal gas at NTP produces a pressure change of 0.001 dyne/cm2 during adiabatic compression. The corresponding change in temperature (γ=1.5 for the gas and atmospheric pressure is 1.013 x106 dynes/cm2) is

A voltameter has internal resistance r ohms and range V volts.The value of resistance used in series to convert it into a voltmeter of range 4V volts is

A liquid of mass m and specific heat S is heated to a temperature T. Another liquid of mass mil and specific heat 2 S is heated to temperature 2 T. If these two liquids are mixed, the resultant temperature of the mixture :

In a meter bridge a 30 Ω resistance is connected in the left gap and a pair of resistances P and Q in the right gap. Measured from the left, the balance point is 37.5 cm, when P and Q are in series and 71.4 cm when they are parallel. The values of P and Q (in Ω ) are

A proton of mass m charge e is released from rest in a uniform electric field of strength E.The time taken by it to travel a distance d in the field is

A small square loop of wire of side l is placed inside a large square loop of side L(L>>1). If the loops are coplanar and their centres coincide, the mutual induction of the system is directlv proportional to :

Four bulbs each marked 40 W. 250 V are connected in series with 250 V source. The total power output is

The displacement of a particle executing SHM is given by y = 5 sin (4t + π/3 ) of T is the time period and the mass of the particle is 2 gms, the kinetic energy of the particle when t = T/4 is given by

Photons of energy 2.0 eV and wavelength λ fall on a metal plate and release photoelectrons with a maximum velocity v.By decreasing X by 25% the maximum velocity of photoelectrons is doubled. The work function of the material of the metal plate,in eV is:

a sonometre has 25 forks. Each produces 4 beats with the next one. If the max frequency is 288Hz,which is the frequency of last fork. The lowest frequency is

A gun is aimed at a target in line with its barrel. The target is released and allowed to fall under gravity, at the instant, the gun is fired. The bullet will :

The potential energy of a proton is 3.2x10-18J at a particular point. The electric potential at this point is

A cylindrical resonance tube open at both ends has a fundamental “f” in air.If half of the length is dipped vertically in water,the fundamental frequency of the air column will be

The natural frequency of an I.-C circuit is 1,25,000 cycle/s. Then the capacitor C is replaced by another capacitor with a dielectric medium of dielectric constant K. In this case, the frequency decreases by 25 kHz. The value of K is

When a vibrating tuning fork is placed on a sound box of a sonometer, 8 beats per second are heard when the length of the sonometer wire is kept at 101 cm or 100 cm. Then the frequency of the tuning fork is (consider that the tension in the wire is kept constant)

Identify the increasing order of the angular velocities of the following :1.earth rotating about its own axis2.hour's hand of a clock3.second's hand of a clock4.flywheel of radius 2 m making 300 rpm

Two wires are fixed on a sonometer wire. Their tensions are in the ratio 8 : 1, the lengths in the ratio 36 : 35, the diameters in the ratio 4 : 1 and densities in the ratio 1 : 2. If the string of higher pitch has frequency of 360 Hz the frequency of the other string is(approximately)

Two charges of +200μC and -200μC are placed at the corners B and C of an equilateral triangle ABC of side 0.1m.The force on a charge of 5μC placed at A is

The frequency of a tuning fork x is 5% greater than that of a standard fork of frequency K.The frequency of another fork y is 3% less than that of K.When x and y are vibrated together 4 beats are heard per second.The frequencies of x and y are

A long rigidly supported wire carries a current ia=96A.Directly above it and parallel to it at a distance,another wire of 0.144N weight per metre carrying a current ib=24A,in a direction opposite to that air due to magnetic repulsion,then its distance(in mm) from the lower wire is

A simple microscope is rated 5x for a normal relaxed eye.what will be its magnifying power for a far sighted man whose near point is 40 cm.

Photoelectric current can be increased by using :

Emission of electrons in photoelectric effect is possible if :

Twelve cells, each having emf E.volts are connected in series and are kept in a closed box. Some of these cells are wrongly connected with positive and negative terminals reversed. This 12 cell battery is connected in series with an ammeter, an external resistance R ohms and a two-cell battery (two cells of the same type used earlier, connected perfectly in series). The current in the circuit when the 12-cell battery and 2-cell battery aid each other is 3A and is 2A when they oppose each other. Then, the number of cells in 12-cell battery that are connected wrongly is :

Three unequal resistors in parallel are equivalent to a resistance 1 ohm. If two of them are in the ratio 1:2and if no resistance value is fractional the largest of the three resistances in ohms is

Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-clad interface.Reason (R): Refractive index of the material of the core of the optical fibre is greater than that of air.

A step down transformer has a supply line voltage of 2200V in to 220V. The primary coil has 5000 turns. The efficiency and power transmitted by the transformer are 90% and 8 kilowatt respectively. Then the number of turns in the secondary is

The weight of a man in a lift moving upwards is 608 N while the weight of the same man in the lift moving downwards, with the same acceleration is 368 N. His normal weight in N is:

A wire stretches by 0.01 m when it is stretched by a certain force.Another wire of the same material but double the length and double the diameter is stretched by the same force.The elongation is

There is no couple acting when two bar magnets are placed coaxially separated by a distance because:

An ammeter whose resistance is 180 Ω shows full scale deflection when the current is 2mA.The shunt required to convert into an ammeter reading 20 mA is (in ohm)

In a chemical reaction, ΔH=150KJ and ΔS=100JK-1 at 300K. ΔG would be

A free neutron decays spontaneously into :

With a standard rectangular bar magnet of length (l), breadth (b; b < < l) and magnetic moment M, the time period of the magnet in a vibration magnetometer is 4 s. If the magnet is cut normal to its length into four equal pieces, the time period (in seconds) with one of the pieces is :

Degenerate electron pressure will not be sufficient to prevent core collapse of 'white dwarf' if its mass becomes n times of solar mass. Value of n is:

A transistor having a β equal to 80 has a change in base current of 250μA,then the change in collector current is :

When an air column of length ‘l’ open at both ends vibrates in its fundamental note, the wavelength is given by

The magnitude of the force between parallel conductors, each of length 110 cm,carrying a current of 10A and separated by a distance of 10 cm is

The velocity of propagation of sound is 330 m/s, in air. If the third harmonic of the fundamental that can be exerted in an open ended tube is 450 Hz, the length of the tube is :

An electron beam moving with a speed of 2x107ms-1 enters a magnetic field of induction 3x10-3T, directed perpendicular to its direction of motion. The intensity of electric field applied so that the electron beam is undeflected due to the magnetic field is

Charges +50,+20,+30 and -100 nano coulomb are placed at the four corners of a square of side 5√2cm.The potential at the intersection point of diagonals is

Two wires A and B,made of same material and having their lengths in the ratio 6:1 are connected in series.The potential differences across the wires are 3V and 2V respectively.If rA and rB the radii of A and B respectively,then rA/rB is

The objective of a telescope has focal length 120cma and diameter 5cm.The focal length of the eye piece is 2cm.The magnifying power of the telescope for distant object is

A condenser of capacity 10 μF is charged to a potential of 500 V. Its terminals are then connected to those of an uncharged condenser of capacity 40 μF. The loss of energy in connecting them together is

The difference between volume and pressure coefficients of an ideal gas is :

The mass of a planet is half that of the earth and the radius of the planet is one-fourth that of earth. If we plan to send an artificial satellite from the planet, the escape velocity will be, (escape velocity on earth ve =11 km- s-1)

A tuning fork vibrating with a sonometer wire of length 20cm produces 5 beats per second. The beat frequency does not change if the length of the wire is changed to 21 cm. The frequency of the tuning fork must be

Along the x-axis, three charges q/2 , -q and q/2 are placed at x = 0, x = a and x = 2a respectively. The resultant electric potential at a point P located at a distance r from the charge -q ( a << r ) is ( εo is the permittivity of free space )

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

Note:

- Click the 'Submit Test' button given in the bottom of this page to Submit your answers.
- Test will be submitted automatically if the time expired.
- Don't refresh the page.

A to Z Exams © 2016