Explanation: Silver. The material that allows flow of electric current with little or no resistance are called conductors. Examples – Copper, Aluminum, human body. Glass, mica, rubber and Ebonite are insulators.

Explanation: Switch – It is a device used to interrupt the flow of electrons in a circuit. Insulator – A material in which electric current does not flow freely. Examples – Glass, air, wood, plastic and rubber.

Explanation: The resistance of a wire is directly proportional to its length and inversely proportional to its cross -sectional area. Resistance is a measure of the opposition to current flow in an electrical circuit. It is measured in ohm (Ω). Factors affecting resistance – Material’s conductivity, Length, Cross-sectional area and Temperature.

Explanation: 6 Ω. Voltage = 18 V, Current = 3 A. Since, Voltage (V) = Resistance (R) × Current (I). Resistance = . 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 𝐶𝑢𝑟𝑟𝑒𝑛𝑡 Resistance = = 6 Ω. 18 3

Explanation: at right angles to the magnetic field. The induced current is highest when the direction of motion of the coil is at 90° or perpendicular with respect to the magnetic field, as the flux cutting is maximum in this case. While it is minimum when the direction of motion of the coil is at 180° or parallel with respect to the magnetic field, as here the flux cutting by the coil will be minimum.

Explanation: I = Q/t. The S.I unit of charge is coulomb, time is second, then current in units of coulomb per second is ‘ampere’. Another formula for calculating current is I = V/R (derived by Ohm’s law), where I = current flowing through the conductor, V = Voltage, and R = Resistance (at constant temperature).

Explanation: Maxwell’s corkscrew rule (Right hand thumb rule). Fleming’s left-hand rule is used to find the direction of the force acting on the current carrying conductor placed in a magnetic field. Fleming’s right hand rule is used to find the direction of induced current when a conductor moves in a magnetic field.

Explanation: Gustav Robert Kirchhoff. Kirchhoff’s first law (Kirchhoff’s junction rule). Kirchhoff’s second law (Kirchhoff’s loop rule) – The directed sum of the potential differences (voltages) around any closed loop is zero. Victor Franz Hess discovered cosmic rays.

Explanation: four. A Wheatstone bridge circuit {invented by Samuel Hunter Christie (1833), popularized by Sir Charles Wheatstone (1843)} consists of four arms (two arms – known resistances, an unknown resistance and a variable resistance}. It works on the principle of null deflection, i.e., when the Wheatstone bridge is balanced the ratio of their resistances are equal and no current flows through the galvanometer.

Explanation: The commonly used wire in the fuse is an alloy of tin (Sn) and lead (Pb). An electrical fuse is a circuit safety device to protect electrical systems.

Explanation: A dipole moment (vector quantity) is a measurement of the separation of two opposite electrical charges. Dipole moment(μ) = q × r (q = charge, r = distance between the charges). Direction is from negative charge to positive charge.

Explanation: It decreases. The magnitude of the magnetic field produced at a given point increases as the current through the wire increases. Magnetic field is the region around a moving charge that generates a field. SI Unit of Magnetic Field Intensity – Tesla (T).

Explanation: 24 J. Potential difference defined as the work done to move unit electric charge from one point to another in an electric circuit. It is given by: V = W/Q; i.e. W = V × Q; W= 6 × 4= 24 joules.

Explanation: Element. Nichrome wire is used as a heating element because it is very stable, even at high temperatures.

Explanation: Coulomb’s Law. According to Coulomb’s law, the force of attraction or repulsion between two charged bodies is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. It acts along the line joining the two charges considered to be point charges. F = . 𝐾𝑞 1 𝑞 2 / 𝑟 2

Explanation: Ampere or amp (symbol: A) is the SI unit of electrical current, which is a flow of electrical charge carriers, usually electrons. A coulomb (C) is the SI unit of electric charge.

Explanation: Electrons move for the flow of charges in a conducting metallic wire only if there is a difference of electric pressure. An electron is a negatively charged subatomic particle. Electron was discovered by J.J Thomson.

Explanation: Ohm’s law (V = IR) states that the electrical current (I) flowing in a circuit is proportional to the voltage (V) and inversely proportional to the resistance(R). So, if the resistance becomes doubled then-current becomes half because the current is inversely proportional to resistance. This law was discovered by Georg Simon Ohm in 1827. Formula : V = IR.

Explanation: The longer, thinner line represents the positive terminal. An electric cell is a device, which converts chemical energy into electrical energy.

Explanation: Magnetic field lines are continuous loops, all closed surfaces have as many magnetic field lines going in as coming out. Hence, the net magnetic flux through a closed surface is zero.

Explanation: Diamond. As diamond is a giant covalent structure, the four outermost electrons, four carbon atoms, are engaged or trapped in the covalent bonds which means that there are no free electrons. So diamonds are a bad conductor of electricity.

Explanation: Michael Faraday introduced the concept of electric field. An electric field is created by a charged body in the space that surrounds it and results in a force exerted on any other charges placed within the field.

Explanation: 0. An electric dipole is a pair of equal and opposite charges, therefore the total charge in an electric dipole will be zero.

Explanation: Metals are good conductors due to the presence of free electrons and when we increase the temperature, the metal ions start vibrating which leads to the increase in resistance so the conductivity is decreased.

Explanation: 0.5 km/minute2 . Given : Final velocity, v = 70 km/h = km/min. Initial 7 6 velocity, u = 10 km/h = km/min. Time 1 6 period, t = 2 min. We know that, Average acceleration, a = = 𝑣−𝑢 𝑡 7 6 – 1 6 2 = = 0.5 km/min2 . 1 2

Explanation: The ‘atm’ is mostly used for measuring and describing atmospheric pressure. ‘bar’ is also used for atmospheric pressure but is also used to measure the pressure inside vessels. 1 bar = 0.986923 atm. 1 atm = 1.01325 bar. Other units: 1 Quart = 32 fluid ounces or 4 cups, 1 Yard = 3 feet or 36 inches (0.9144 meters), 1 Gallon = 3.785 liters.

Explanation: The law of inertia was inferred by Galileo from observations of motion of a ball on a double inclined plane. Galileo concluded that an object moving on a frictionless horizontal plane must neither have acceleration nor retardation, i.e. it should move with constant velocity.

Explanation: Torque = Force × Distance, SI unit – newton-metre, Dimension – [M1L 2 T -2]. Power : It is the work done in unit time. Power = W/t, SI unit – watt, Dimension – [M1 L 2 T -3]. Moment of inertia: The quantity expressed by the body resisting angular acceleration. I = L/⍵. where; I = inertia, L = angular momentum, ⍵ = angular velocity. SI unit – kg⋅m2 . Dimension – [M¹ L² T⁰]. Centripetal Force: A force that acts on a body moving in a circular path and is directed towards the center around which the body is moving.

Explanation: Impulse. Force – The push or pull on an object with mass causes it to change its velocity. Pressure – The force acting on a unit area of a surface. Surface tension – The property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules. Tensile stress – Capacity of a material to endure a pulling (tensile) force.

Explanation: 1 atm = 1.013 bar. ‘bar’ and ‘atm’ are the units representing pressure. A pascal (SI Unit of pressure) is one newton of force acting on 1 square meter area. An atmosphere (atm) is a unit of measurement equal to the average air pressure at sea level at a temperature of 15 degrees Celsius. Atmospheric pressure drops as altitude increases.

Explanation: According to 1 2𝑚 ℎ π Heisenberg’s uncertainty principle : Δx.Δp = ℎ 4π Δx × m × Δv = . ℎ 4π Given that, Δx = mΔv then, mΔv × mΔv = ℎ 4π 𝑚 = . 2 ∆𝑣 2 ℎ 4π ∆𝑣 = = ℎ 4π 1 𝑚 1 2𝑚 ℎ π

Explanation: Pascal’s law : When a fluid is at rest, the pressure is the same at all points located at the same height. Graham’s law of diffusion : It describes the relationship between the rate of diffusion and the densities of gases. R1/R2 = (M2/M1) 1/2 , where R1 , R2 are diffusion rates of gases 1 and 2, and M1 and M2 their respective molecular masses. The law is a simple consequence of kinetic theory. Torricelli’s Law : It describes the relationship between the exit velocity of an ideal fluid from a small hole and the depth of fluid above that hole.

Explanation: long spans. Post tensioning is a technique for reinforcing concrete, in which prestressing steel cables inside plastic ducts are positioned in the forms before the concrete is placed. Pretensioning – The technique in which we are imparting tension in strands before placing the concrete. It is more durable and reliable.

Explanation: Frictional force is the resistance encountered when two surfaces slide or attempt to slide against each other, resulting from the interaction between their roughness and molecular forces. Formula – F (friction force) = μ (coefficient of friction) × N (normal force). Normal Force – The force that surfaces exert to prevent solid objects from passing through each other. Coefficient of friction : It is a measure of the amount of friction existing between two surfaces.

Explanation: Speed. Centripetal acceleration – That is directed towards the center of the circle. It is caused by the change in direction of the velocity vector as the object moves around the circle. Centripetal Acceleration (ac) formula: ac = v 2/r (where v is the speed, r is the radius). Dimensional formula of centripetal acceleration = [ M0L 1T -2 ].

Explanation: Centripetal. Examples of Centripetal Force – Loop of Roller Coaster, Orbiting Planets. Centrifugal – Force experienced by an object traveling in a circle, directed away from the center of the circle. Examples – Washing Machine dryer. Gravitational – The force of attraction between objects with mass. Examples – Tides, falling Objects. Van der Waals forces – Weak intermolecular forces of attraction between molecules, arising from temporary fluctuations in electron density.

Explanation: Law of Inertia. Newton’s first law of motion – A body remains in the state of rest or uniform motion in a straight line unless and until an external force acts on it.

Explanation: Static Friction – Force that keeps an object at rest. Kinetic Friction – It is a force that acts between moving surfaces. Centripetal Friction – The frictional force supplies the centripetal force and is numerically equal to it.

Explanation: Electrostatic force – This force between two charged particles is directly proportional to the product of the charges and inversely proportional to the square of the distance between the particles. The same charge on two particles – the force will be repulsive and the opposite charge on the particles – the force will be attractive.

Explanation: Lubricants – Any substance that is physically integrated for the purpose of reducing friction between two or more moving surfaces. Examples – Grease and oil. Fluid – Substances which can flow easily. Examples – Water, oil, air. Magnet – Material that can produce its own magnetic field. Examples – Neodymium and samarium cobalt. Spring – Device consisting of an elasticity but made of rigid material.

Explanation: Air pressure is defined as the pressure exerted by the weight of air on the earth’s surface. When there is a larger pressure difference between the pressure zones, the wind travels quicker and it travels from an area of high pressure to low pressure.

Explanation: 6000 units. We know that Momentum is directly proportional to the object’s mass (m) and velocity (v). Momentum (p) = mass (m) × velocity (v). And if velocity is doubled, momentum is also doubled. Hence momentum = 2 × 3000 = 6000 units.

Explanation: Newton’s third law of Motion – States that to every action, there is an equal and opposite reaction. Force : The push or pull on an object with mass causes it to change its velocity. SI unit of Force – Newton. Dimension of Force – [MLT-2 ]. CGS unit of Force – dyne.

Explanation: Friction. Contact force – Any force that occurs as a result of two objects making contact with each other. Examples – Friction force, Muscular force. Non-contact force – The force applied on an object without any contact with it. Examples – Magnetic force, electrostatic forces, gravitational force.

Explanation: Static > Sliding > Rolling. Static Friction : A force that hinders the movement of an object moving along the path. Sliding Friction : Resistance created by any two objects when sliding against each other. Rolling Friction : The force resisting the motion of a rolling body on a surface.

Explanation: Greater the mass, greater the inertia. As inertia is directly proportional to the mass of the object (I = mr2 ) so Inertia will increase if mass increases. Inertia is defined as a property of matter by which it tries to maintain its state of rest or of uniform motion along a straight line. Types of Inertia include Inertia of Rest, Inertia of Motion and Inertia of direction.

Explanation: Freely falling. When an object is traveling in a straight line with an increase in velocity at equal intervals of time, then the object is said to be in uniform acceleration. Parabolic motion is the motion of an object traveling along a path in the shape of a parabola, such as The path of a golf ball and The throwing of a stone.

Explanation: Uniform motion – When an object covers equal distances in equal intervals of time, then its motion is called uniform motion. Example – Motion of the blades of a ceiling fan. Non-uniform motion – Objects move with different speeds and do not cover equal distances in equal intervals of time. Example – Speed of train.

Explanation: Distance. In this graph, the slope of the line is equal to the speed of the object. Speed and distance are scalar quantities. Velocity (Displacement-time graph, vector quantity). Acceleration (velocity – time graph, vector quantity), Displacement (vector quantity).

Explanation: Newton’s laws of motion. Third Law is often given as an explanation for the generation of thrust (to every action, there is an equal and opposite reaction).