Question 1 :
If a current of 3 A flowing in the primary coil is reduced to zero in 0.001 s, the induced emf in between the two coils is 15000 V, the coefficient of mutual induction is
Question 2 :
The maximum value of AC voltage in a circuit is 707 V. Its rms value is
Question 4 :
A boat is moving due east in a region where the earth's magnetic field is {tex} 5.0 \times 10 ^ { - 5 } \mathrm { NA } ^ { - 1 } \mathrm { m } ^ { - 1 } {/tex} due north and horizontal. The boat carries a vertical aerial {tex} \mathrm { 2m } {/tex} long. If the speed of the boat is {tex} \mathrm { 1.50ms } ^ { - 1 } {/tex} , the magnitude of the induced emf in the wire of aerial is:
Question 5 :
A bulb is connected first with dc and then ac of same voltage it will shine brightly with
Question 6 :
For a series <i>L-C-R</i> circuit at resonance, the statement which is not true is
Question 7 :
When current in a coil changes from 2 A to 4 A in 0.05s, an emf of 8 V is induced in the coil. Self inductance of the coil is
Question 8 :
Large transformers, when used for some time, become hot and are cooled by circulating oil. The heating of transformer is due to
Question 9 :
Whenever a magnet is moved either towards or away from a conducting coil, an emf is induced, the magnitude of which is independent of
Question 10 :
A 50 mH coil carries a current of 2 A, the energy stored in joule is
Question 12 :
A magnet is brought towards a coil (i) speedly (ii) slowly, then the induced e.m.f /induced charge will be respectively
Question 13 : In the circuit shown, when the switch is closed, the capacitor charges with a time constant<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60f09ad3eb695bc07eb5a7"><br>
Question 15 :
The resistance of the coil of an ammeter is {tex} R {/tex} . The shunt required to increase its range {tex} n {/tex} -fold should have a resistance
Question 16 :
A wire of length 5 m and radius 1 mm has a resistance of 1 ohm. What length of the wire of the same material at the same temperature and of radius 2 mm will also have a resistance of 1 ohm?
Question 17 :
In a neon gas discharge tube Ne' ions moving through a cross-section of the tube each second to the right is {tex} 2.9 \times {/tex} {tex} 10 ^ { 18 } {/tex} , while {tex} 1.2 \times 10 ^ { 18 } {/tex} electrons move towards left in the same time; the electronic charge being {tex} 1.6 \times 10 ^ { - 19 } \mathrm { C } , {/tex} the net electric current is
Question 18 :
In a large building, there are 15 bulbs of {tex} 40 \mathrm { W } , 5 {/tex} bulbs of 100 {tex} \mathrm { W } , 5 {/tex} fans of 80{tex} \mathrm { W } {/tex} and 1 heater of 1{tex} \mathrm { kW } {/tex} . The voltage of electric mains is 220{tex} \mathrm { V } {/tex} . The minimum capacity of the main fuse of the building will be:
Question 19 : Find emf {tex} \mathrm { E } {/tex} of the cell as shown in figure.<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d6111c3e5db655bbf10a908"><br>
Question 20 : In the circuit shown, the current through 8 ohm is same before and after connecting E. The value of {tex} E {/tex} is<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d6111bde5db655bbf10a903"><br>
Question 21 : The equivalent resistance between the points A and B in the following circuit is <img style='object-fit:contain' src='https://storage.googleapis.com/teachmint/question_assets/NEET/5bad8e9adb1af5706f171abc'>
Question 22 :
An electric current is passed through a circuit containing two wires of the same material, connected in parallel. If the lengths and radii are in the ratio of {tex} \frac { 4 } { 3 } {/tex} and {tex} \frac { 2 } { 3 } , {/tex} then the ratio of the current passing through the wires will be
Question 23 :
A battery is charged at a potential of 15{tex} \mathrm { V } {/tex} for 8 hours when the current flowing is 10{tex} \mathrm { A } {/tex} . The battery on discharge supplies a current of 5{tex} \mathrm { A } {/tex} for 15 hours. The mean terminal voltage during discharge is 14{tex} \mathrm { V } {/tex} . The "watt-hour" efficiency of the battery is
Question 25 :
A bar magnet of magnetic moment {tex} M {/tex} is placed at right angles to a magnetic induction {tex} B {/tex} . If a force {tex} F {/tex} is experienced by each pole of the magnet, the length of the magnet will be
Question 26 :
Resultant force acting on a diamagnetic material in a magnetic field is in direction
Question 27 :
A paramagnetic liquid is taken in a U-tube and arranged so that one of its limbs is kept between pole pieces of the magnet. The liquid level in the limb
Question 28 :
Substances in which the magnetic moment of a single atom is not zero, is known as
Question 29 : A uniform magnetic field acts at right angles to the direction of motion of electrons. As a result, the electron moves in a circular path of radius <img style='object-fit:contain' width=31 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1bf3727ce131ff7c08b47"> . If the speed of the electrons is doubled, then the radius of the circular path will be
Question 30 :
A stream of electrons is projected horizontally to the right. A straight conductor carrying a current is supported parallel to electron stream and above it. If the current in the conductor is from left to right, then what will be the effect on electron stream?
Question 32 :
Which one of the following characteristics is not associated with a ferromagnetic material?
Question 33 :
Two parallel wires carrying currents in the same direction attract each other because of
Question 34 : An electron travelling with a speed u along the positive {tex} x {/tex} -axis enters into a region of magnetic field where {tex} B = - B _ { 0 } \hat { k } ( x > 0 ) . {/tex} It comes out of the region with speed {tex} \mathrm { v } {/tex} then<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60ef35e5db655bbf10a496">
Question 35 :
A loosely wound helix made of stiff wire is mounted vertically with the lower end just touching a dish of mercury. When a current from a battery is started in the coil through the mercury
Question 36 :
A circular coil of radius {tex} \mathrm { r } {/tex} carries a current I. If the same coil is now changed into a square loop carrying the same current, magnitude of its magnetic moment will
Question 37 :
The angle of dip at a place is {tex} 37 ^ { \circ } {/tex} and the vertical component of the earth's magnetic field is {tex} 6 \times 10 ^ { - 5 } \mathrm { T } {/tex} . The earth's magnetic field at this place is {tex} \left( \tan 37 ^ { \circ } = 3 / 4 \right) {/tex}
Question 38 :
When a charged particle moving with velocity is subjected to a magnetic field of induction {tex} \overrightarrow { \mathrm { B } } , {/tex} the force on it is non- zero. This implies that
Question 39 : In the given figure, what is the magnetic field induction at point {tex} \mathrm { O } ? {/tex}<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e99a40fdebb574cf701648f"><br>
Question 40 :
Alpha particles {tex} \left( \mathrm { m } = 6.7 \times 10 ^ { - 27 } \mathrm { kg } , \mathrm { q } = + 2 \mathrm { e } \right) {/tex} are accelerated from rest through a potential difference of 6.7 {tex} \mathrm { kV } {/tex}. Then, they enter a magnetic field {tex} \mathrm { B } = 0.2 \mathrm { T } {/tex} perpendicular to them direction of their motion. The radius of the path described by them is
Question 42 :
A uniform electric field and a uniform magnetic field exist in a region in the same direction. An electron is projected with a velocity pointed in the same direction. Then the electron will
Question 44 :
If a dielectric substance is introduced between the plates of a charged air-gap capacitor. The energy of the capacitor will
Question 46 :
Consider a neutral conducting sphere. A positive point charge is placed outside the sphere. The net charge on the sphere is then
Question 47 : Potential energy of two equal negative point charges 2<img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5efc8ae8a72b9e1b87abfe6a"/>C each held 1 m apart in air is
Question 48 :
When the distance between the charged particles is halved, the force between them becomes
Question 49 : A, B and C are three points in a uniform electric field. The electric potential is<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d5fce6f06864d5bec7bea7a"><br>
Question 51 : An electric dipole has a pair of equal and opposite point charges <i>q</i> and <i>q </i>separated by a distance <img style='object-fit:contain' width=16 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea183781ac76a0b860fd432"> . The axis of the dipole is defined as
Question 52 :
If a unit positive charge is taken from one point to another over an equipotential surface, then
Question 53 :
If <i>E<sub>a</sub></i><sub> </sub>be the electric field strength of a short dipole at a point on its axial line and <i>E<sub>e</sub> </i>that on equatorial line at the same distance, then
Question 55 :
One of the following is not a property of field lines
Question 56 :
The work done in carrying a charge q once around a circle of radius {tex} r {/tex} with a charge {tex} Q {/tex} placed at the centre will be
Question 57 : If dielectric constant and dielectric strength be denoted by <img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5efc8af0a72b9e1b87abfe9a"/> and<img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5efc8c56f8ed356eae022b74"/>X respectively, then a material suitable for use as a dielectric in a capacitor must have
Question 58 :
The electric charges are distributed in a small volume. The flux of the electric field through a spherical surface of radius 10 cm surrounding the total charge is 20 Vm. The flux over a concentric sphere of radius 20 cm will be
