AFNS Most Repeated MCQs Physics
Question | Answer |
Beats are produced due to? | Interference |
Viscosity in solids is? | No Concept |
Unit of charge is? | Coulomb |
Electron volt is a unit of? | Energy |
Torque is the product of? | Force and radius vector |
Unit of dipole moment? | Ampere Second Meter |
A train of mass 8000Kg is moving with constant speed, then the net force acting on it is? | Zero |
Acceleration is? | Vector Quantity |
A device that can store charges? | Capacitor |
First law of motion of Newton is also called? | Law of Inertia |
The rate of doing work is called? | Power |
Unit of energy is? | Joule |
Earth moves around the sun according to which law? | Kepler’s 2nd Law |
Unit of charge is? | Coulomb |
In which law is pressure kept constant? | Charles’ Law |
Ohm is the unit of? | Resistance |
The path followed by a projectile is? | Trajectory |
Electron volt is the unit of? | Energy |
Magnetic induction is also called? | Magnetic Flux Density |
Unit of viscosity is? | Meter²/sec |
The unit of surface tension is? | Newton/meter |
Which is not a vector quantity? | Mass |
The direction of the induced current always opposes the change which causes it? | Lenz’s Law |
Which shows the energy of orbits? | Bohr Atomic Model |
Earth revolves around the sun according to which law? | Law of Motion |
When a body moves in a circular path with constant speed, then force acting on it is? | Zero/No Force |
Atom bomb is based on the principle of? | Nuclear Fission Reaction |
Question | Answer |
The unit of efficiency is? | No Unit |
Study of neutrons, atoms, electrons is in which branch of physics? | Atomic Physics |
Rate of change of displacement is? | Velocity |
In order to do work, energy? | Transferred/Convert |
The SI unit of electric current is? | Ampere |
ERG (electroretinography) test is for? | Eyes |
Which bulb has higher resistance: 100W or 2W? | 2 Watt |
Long sightedness is corrected by using? | Convex lens |
The SI unit of Electric dipole moment is? | Ampere Second Meter |
Which bulb has lower resistance: 100W or 60W? | 100 Watt |
The unit of heat is? | Joule |
Tesla is the unit of? | Magnetic Field/Magnetic Induction |
The energy which is due to motion? | Kinetic Energy |
Potential energy and kinetic energy are examples of? | Mechanical Energy |
A 250V bulb passes a current of 0.3A. Calculate the power. | 75 Watt |
Total photosynthesis carried out by terrestrial plants is? | 20% |
The unit of force constant is? | Newton/meter |
The work is equal to the product of? | Force and Displacement |
Does a pen write on paper due to force? | Yes (Force of Friction) |
In physics, we study the relation between? | Matter and Energy |
Unit of Force Constant is? | N/m |
Unit of dipole moment? | Ampere Second Meter |
Unit of viscosity is? | Ns/m² |
A body rotating with constant angular acceleration, its centripetal force will be? | Constant |
Solid NaCl is? | Insulator |
An electric motor converts which energy into mechanical energy? | Electrical |
When a craft moves in space, which law of motion applies? | 3rd Law of Motion |
Who proposed the Pressure Flow Theory? | Ernst Munch |
Question | Answer |
The unit of force constant is | N/m |
The energy that it possesses due to its motion is called | Kinetic Energy |
Rate of change of displacement is called | Velocity |
The unit of Efficiency is | No unit |
One nanosecond equals how many seconds? | 10⁻⁹ |
Acceleration is a | Vector quantity |
Gravity at the center of the Earth is | Zero |
Device that converts electrical power into coherent light? | Laser Diodes |
Each orbital can hold a maximum of how many electrons? | Two |
The maximum range for projectile motion is | 45° |
How many joules are in 1 calorie? | 4.18 Joules |
A photon loses its entire energy during | Photoelectric effect |
In case of positive work, the angle between force and displacement is | 0° (zero degree) |
In case of negative work, the angle between force and displacement is | 180° |
Unit of Magnetic Flux is | Weber (Wb) |
The SI unit of Magnetic Flux density is | Tesla |
How many faces does a prism have? | Faces depend on prism shape |
The SI unit of capacitance is | Farad (F) |
One horsepower is equal to | 746 watts |
Which force attracts each body toward itself? | Gravitational Force |
A body travels at a uniform speed of 20m/s. Find the distance covered in 10 sec. | 200 meters |
Electron volt is the unit of | Energy |
If two forces of 3N and 4N act on a body at a 90° angle, the magnitude of the resultant force will be | 5N |
Scalar product is also called | Dot Product |
Which bulb gives more brightness: 60W or 100W? | 100W |
Distance covered by a body in unit time is called | Speed |
One nanosecond is equal to | 10⁻⁹ seconds |
Question | Answer |
Centripetal force acts on? | An object moving in a circle |
Light year is the unit of? | Distance |
What is the weight of a body at the center of the Earth? | Zero |
The unit of resistance is? | Ohm (Ω) |
The force that causes an object to rotate about an axis is called? | Torque |
The field of physics that studies atoms as an isolated system of electrons and an atomic nucleus is called? | Atomic physics |
The Sun is a? | Star |
Sound waves are waves. | Longitudinal waves |
Which bulb has higher resistance, 100 watts or 2 watts? | 2 watts |
ERG (Electroretinography) test is for? | Eyes |
The study of atoms, neutrons, and electrons falls under which branch of physics? | Atomic physics |
Distance covered by a body in unit time is called? | Speed |
Scalar product is also called? | Dot product |
Electron Volt is the unit of? | Energy |
A body travels at a uniform speed of 20 m/s. Find the distance covered in 10 seconds. | 200 m (Formula: S = vt) |
Which bulb gives more brightness, 100 watts or 60 watts? | 100 watts |
The SI unit of Electric Dipole Moment is? | Coulomb-meter |
What type of lens is used to correct long-sightedness? | Convex lens |
What happens when two parallel wires carry current in the same direction? | They attract each other |
What happens when two parallel wires carry current in opposite directions? | They repel each other |
A Venturimeter is a device used to measure? | The rate of fluid flow through a pipe |
A device used to convert DC into AC is? | Power Inverter |
A device used to convert AC into DC is? | Rectifier |
The dimension of Angular Momentum is? | [M¹][L²][T⁻¹] |
The acceleration of a freely falling body is? | 9.8 m/s² |
The dimension of Impulse is similar to? | Momentum (Formula: Ns) |
When a ray of light enters a glass slab from air, what happens? | Its wavelength decreases |
The SI unit of Frequency is? | Hertz (Hz) |
The dimension of mass is? | [M] |
What is the weight of a body placed at the center of the Earth? | Zero |
The SI unit of viscosity is? | Pascal-second (kg·m⁻¹·s⁻¹) |
Hooke’s Law is applicable within? | The elastic limit |
The SI unit of self-inductance is? | Henry (H) |
The SI unit of capacitance is? | Farad (F) |
How many basic SI units are there? | Seven |
The unit of stress is? | Newton per square meter (N/m²) |
The period of a simple pendulum will be doubled if? | The length is increased four times |
In the case of a concave mirror, the center of curvature lies? | In front of the mirror |
The frequency of a Second Pendulum is? | 0.5 Hz |
The unit of heat is? | Joule |
Tesla is the unit of? | Magnetic field |
Question | Answer |
The path followed by a projectile is known as? | Trajectory |
How many sides does a prism have? | 6 |
Which of the following is not a vector? | Displacement |
What is the unit of viscosity? | No correct option provided |
What is the unit of charge? | Coulomb |
Ohm is the unit of? | Resistance |
A device that can store charge? | Capacitor |
The unit of surface tension? | Newton per meter |
Electron Volt is the unit of? | Energy |
A thermostat is an instrument that maintains? | Temperature |
The unit of heat is? | Joule |
Tesla is the unit of? | Magnetic field |
The energy due to motion is called? | Kinetic energy |
The Earth revolves around the Sun by which law? | Law of motion |
The rate of change of displacement is called? | Velocity |
A decrease in speed or velocity is called? | Deceleration |
The unit of efficiency is? | No unit |
Distance covered by a body in unit time is called? | Speed |
The unit of force constant is? | N/m |
The scalar product is also called? | Dot product |
Electron Volt is the unit of? | Energy |
One nanosecond is equal to how many seconds? | 10⁻⁹ |
ERG test is for? | Eyes |
Which force attracts each body towards it? | Gravitational force |
Acceleration is a? | Vector quantity |
What is the unit of Magnetic Flux? | Tesla |
In what condition is work positive? | When the direction of force and displacement is the same |
When a body moves in a circle, what is the effect on kinetic energy? | Kinetic energy = 0 |
Gravity at the center of the Earth is? | Zero |
1 Horsepower is equal to? | 746 watts |
If the time of a pendulum is doubled, what happens to its length? | It increases 4 times |
The range of a projectile is maximum at which angle? | 45° |
How many faces does a prism have? | It depends on the shape of the prism |
The unit of capacitance is? | Farad (named after Michael Faraday) |
The unit of frequency is? | Hertz |
Question | Answer |
What pressure is required to fill the discharge tube? | Less |
What region does the Balmer series lie in? | Visible |
What is the natural arrangement of colors in the spectrum of white light? | VIBGYOR |
What is the range of wavelengths of colors in the visible spectrum? | 410 |
What is the incorrect statement? | 656 |
Who expressed the results of spectra obtained by Balmer in 1896? | Rydberg |
What is the process of formation of spectrum called? | Spectroscopy |
What is the value of Rydberg’s constant? | 1.0974 |
What does spectrum represent? | Wavelength |
Which series lies in the visible region? | Balmer |
Where does the Lyman series exist in the spectrum of hydrogen? | Ultraviolet |
Who suggested the neutron in the nucleus? | Rutherford |
Who discovered the neutron? | Chadwick |
What is the ratio of the radii of an atom and its nucleus? | 10⁴ |
What does nucleon mean? | Both |
What are the charge and mass of a proton? | 1.6×10⁻¹⁹ |
What is the mass of a neutron? | Exactly |
Question | Answer |
What should the J.A be? | 90 |
What is the unit of induced EMF? | Volt |
How is the magnetic flux changed when the coil is placed in the magnetic field of an electromagnet? | Changing |
How is alternating current transmitted over long distances? | High |
What source produces alternating current? | Reverses |
What happens to the polarity of the source after every time interval T/2? | Keeps |
What kind of energy is electrical energy nowadays? | Hydal |
What do A.C generators use? | Hydal |
What is the time interval during which the source changes its polarity? | Half |
What is the most common source of alternating voltage? | Generator |
How is the output voltage of an A.C generator given at any instant? | V₀sinωt |
What is the angle through which the coil of A.C generator rotates? | 2π |
What is the alternating voltage V when t=T/4? | V₀ |
What is the waveform of alternating voltage? | Sine |
What can the instantaneous value of voltage or current have? | Any |
What is the force that maintains the strict long-range order between atoms of a crystalline solid? | Cohesive |
What does the word amorphous mean? | Without |
What kind of melting point do amorphous solids have? | No |
At what temperature does ordinary glass soften into a paste-like state? | 500°C |
What is the pattern of a crystalline solid? | Three |
At what angle do all the sides meet in a cubic crystal? | 90° |
How can the arrangement of molecules or atoms in a crystalline solid be studied? | X-ray |
What is the dimensionality of a unit cell? | Three |
Which is not a crystalline solid? | Glass |
What is the temperature at which the vibrations break up the crystal structure called? | Melting |
What is the whole structure obtained by repetition of unit cells called? | Crystal |
What pattern do NaCl particles have? | Cubic |
What holds atoms in their equilibrium positions in crystalline solids? | Cohesive |
What is the smallest three-dimensional structural unit called? | Unit |
What are computer chips made from? | Silicon |
What is silicon classified as? | Semiconductor |
What has led to huge advances in electronics? | Semiconductors |
What is the use of chips in electronics described as? | Black |
What form does a crystal of germanium or silicon in its pure form at absolute zero act as? | Insulator |
What form does a crystal of germanium or silicon at room temperature act as? | Semiconductor |
What are the atomic number and number of valence electrons in germanium? | 32, 4 |
How are valence electrons in a silicon crystal bound? | Covalent |
How many electrons does a stable configuration possess? | 8 |
What is a p-type crystal? | Neutral |
What are the majority charge carriers in the p-region of a p-n junction? | Holes |
What is created when a covalent bond breaks? | Electron-hole |
What is the impurity ratio in germanium? | 1:10⁶ |
What increases when phosphorus is added to germanium? | Electrons |
What does a hole in p-type may be due to? | Impurity |
What is the concept of direction? | Relative |
What are all motions? | Relative |
When does a body at rest remain at rest? | Unbalanced |
What is the earth strictly speaking? | Accelerated |
What does the special theory of relativity treat? | Inertial |
What does the general theory of relativity treat? | Accelerating |
What would the distance from Earth to a star seem to an observer in a moving spaceship? | Smaller |
What is the special theory of relativity based on? | Two |
What kind of motion is impossible to detect? | Absolute |
What is time? | Relative |
What does the symbol ‘t’ denote in relativity problems? | Proper |
What is the quantity v/c practically always? | Less |
What is the correct statement about mass in relativity? | Greater |
What happens to time due to relative motion? | Dilates |
What happens to the aging process of the human body at very high speed? | Slow |
What kind of quantity is the mass of an object? | Varying |
What is Earth’s orbital speed? | 30 |
What is the ratio of the speed of light to the orbital speed of Earth? | 10⁴ |
What is the first series identified in the hydrogen spectrum called? | Lyman |
When was the Balmer series identified? | 1885 |
How can hydrogen gas atoms be excited? | Passing |
Question | Answer |
What is the force on a current-carrying conductor in a magnetic field proportional to? | Current |
What does the force on a current-carrying conductor in a magnetic field depend on besides current? | Length |
What is the force on a current-carrying conductor in a magnetic field proportional to besides current and length? | Field |
What do magnetic lines of force do? | Cannot |
Where do magnetic lines of force intersect? | Infinity |
Where do magnetic lines of force intersect within a magnet? | Points |
Where do magnetic lines of force intersect? | Neutral |
What is the strength of the magnetic field around a straight conductor? | Same |
What law does the strength of the magnetic field around a straight conductor obey? | Inverse |
What is the strength of the magnetic field around a straight conductor proportional to? | Square |
What shape are the lines of force around a straight wire carrying current? | Circular |
What force does a current-carrying conductor experience perpendicular to a magnetic field? | ILB |
How is the direction of force on a current-carrying conductor found? | Cross |
What is magnetic flux defined as? | AB |
What is the direction of a vector area? | Perpendicular |
What is the flux if the field is along the normal to the area? | Maximum |
What is the unit of magnetic induction? | Weber |
What is magnetic induction defined as flux per unit area? | Perpendicular |
What is the current produced by moving a loop of wire across a magnetic field called? | Induced |
When is an EMF set up in a conductor? | Moves |
How can an induced current be produced? | Changing |
What is the phenomenon of generation of induced EMF called? | Electromagnetic |
What does the induced current in a conductor depend upon? | Resistance |
Where do Michael Faraday and Joseph Henry belong respectively? | England |
What does the magnitude of induced EMF depend upon? | Rate |
What does the galvanometer indicate when there is no relative motion between the magnet and coil? | No |
What does the galvanometer show when the magnet is moved towards the coil instead of moving the coil? | Same |
When is an induced current produced in a coil of constant area in a constant magnetic field? | Rotated |
What happens in the circuit when the switch of coil P is suddenly closed? | Momentary |
What does the galvanometer needle do when the switch is closed? | Deflects |
When does the current in coil P grow from zero to its maximum value? | Instant |
When does the current in coil P fall from its maximum value to zero? | Instant |
What does the change in current in coil P cause? | Induced |
What angle is needed for no EMF to be induced in a flat loop of wire in a changing magnetic field? | Perpendicular |
What is the unit of induced EMF? | Volt |
How is the magnetic flux changed when the coil is placed in the magnetic field of an electromagnet? | Changing |
How is alternating current transmitted over long distances? | High |
What source produces alternating current? | Reverses |
What happens to the polarity of the source after every time interval T/2? | Keeps |
What kind of energy is electrical energy nowadays? | Hydal |
What do A.C generators use? | Hydal |
What is the time interval during which the source changes its polarity? | Half |
What is the most common source of alternating voltage? | Generator |
How is the output voltage of an A.C generator given at any instant? | V₀sinωt |
What is the angle through which the coil of A.C generator rotates? | 2π |
What is the alternating voltage V when t=T/4? | V₀ |
What is the waveform of alternating voltage? | Sine |
What can the instantaneous value of voltage or current have? | Any |
What is the entire waveform of sinusoidal voltage? | Instantaneous |
What is the RMS value of voltage? | V₀/√2 |
What is the highest value reached by the voltage or current? | Peak |
What is the sum of positive and negative peak values called? | Peak-to-peak |
What is the peak-to-peak value of alternating voltage? | 2V₀ |
What is the average value of alternating voltage over a complete cycle? | Zero |
What is the peak value of alternating current? | One |
What is the RMS value of alternating voltage? | 0.7 |
How is zirconia classified? | Ceramic |
What happens to the amplitude of vibration of atoms in a metal crystal with a rise in temperature? | Increases |
What is the transition from solid to liquid? | Order |
What is the transition from solid to liquid? | Abrupt |
What force maintains the strict long-range order of crystalline solids? | Interatomic |
Question | Answer |
What is the SI unit of charge? | Coulomb |
What is the name given to the current due to the flow of positive charges? | Conventional |
What is the SI unit of current that describes the flow of charge at the rate of? | Coulomb |
In the case of metallic conductors, the charge carriers are? | Electrons |
The charge carriers in an electrolyte are? | Positive |
In gases, the charge carriers are? | Electrons |
What is the conventional current the name given to the current due to the flow of? | Positive |
What is the positive charge moving in one direction equivalent to in all external effects? | Negative |
In a metal, the valence electrons are? | Free |
Most practical applications of electricity involve? | Charges |
What is the direction of force on a current-carrying conductor placed in a magnetic field? | Perpendicular |
What is the pointer of a magnetic compass affected only by? | Magnets |
What is a magnetic field? | Vector |
What rule gives the direction of magnetic lines of force around a current- carrying wire? | Right-hand |
Where is the magnetic field associated with a current-carrying copper rod? | Both |
What does the force on a current-carrying conductor depend upon? | Angle |
Question | Answer |
Inflatable bag is a part of: | Sphygmomanometer |
When a quarter of a cycle is completed, the phase of vibration is: | 90 |
Distance covered during one vibration of an oscillating body in terms of amplitude A is: | 4A |
A body of mass 0.031 kg attached to one end of a spring of spring constant 0.3 N/m, then time period of spring mass system will be: | 2.0 |
The time period of a simple pendulum is independent of its: | Mass |
If the time period of a pendulum is doubled by increasing its length, then its frequency will: | Half |
The string of a simple pendulum should be: | Inextensible |
Second’s pendulum is the pendulum whose time period is: | 2 |
An object undergoes SHM. Its maximum speed occurs when its displacement from the equilibrium position is: | Zero |
Free oscillations are always produced by: | Restoring |
If the waves produced in a microwave oven are of wavelength 12 cm, then their frequency will be: | 2500 |
The square root of 0.4 is: | Smaller |
Wavelength and time period T are related to the velocity v of the wave as: | Tv |
The ratio of speed of sound in hydrogen to the speed of sound in oxygen is: | 4:1 |
If the atmospheric pressure is doubled, the speed of sound: | Constant |
Two identical tuning forks vibrate at 256 c/sec. After loading one of them, 6 beats/sec are heard when forks are sounded together. The period of the loaded fork is: | 0.006 |
The effect of loading the prongs of a tuning fork with wax is to: | Decrease |
Given for (cylindrical) metal wire, ρ = 1 kg/m, diameter = 2mm, l = 32 cm, find out mass: | 10 |
The wavelength of sound produced by an open-end organ pipe in nth mode is: | 2l/n |
In which case is Doppler’s effect used: | All |
As an empty test tube is filled with water, the frequency of the air column: | Increases |
Frequency of red color as compared to that of violet color is: | Smaller |
Phase change of 180 is equivalent to a path difference of: | λ/2 |
Conditions for interference are that the two sources should be coherent and: | Close |
To find the wavelength of light by his experiment, Newton utilized: | Phase |
The wavelength of light can be found by means of Michelson Interferometer using the formula: | 2L/m |
A grating has 5000 lines per centimeter. The grating element will be given as: | 2×10^-4 |
Diffraction effect is: | More |
In Bragg’s equation, d represents: | Interplanar |
X-ray diffraction has been used in studying the: | Crystal |
Which of the following cannot be polarized: | Sound |
With age, the least distance of distinct vision: | Increases |
Conventionally, all the distances are measured from: | Optical |
The image of an object 5 mm length is only 1 cm high. The magnification produced by the lens is: | 2 |
Resolving power in mth order diffraction for grating is given by: | mN |
The working of a compound microscope is based on the principle of: | Refraction |
A spectrometer is used to study: | Spectra |
The magnifying power of an astronomical telescope increases with: | Increasing |
In Michelson’s experiment, the rotational mirror and plane mirror were mounted on: | Same |
A material having a high refractive index has: | High |
Avogadro’s number is known as the number of molecules in: | One |
The nature of thermal radiation is similar to: | Light |
In which process, the change in internal energy of the system is zero: | Isothermal |
If A is the area of the piston and dy is the distance moved by the piston, then change in volume is expressed by: | Ady |
Carnot cycle is: | Reversible |
The efficiency of a practical heat engine: | Cannot |
Number of spark plugs needed in a diesel engine is: | None |
No entropy change is associated with: | Adiabatic |
Only those processes are probable to take place for which entropy of the system: | Increases |
When heat is added to the system, the entropy change is: | Positive |
If the distance between two charges is doubled, the force between them will become: | One-fourth |
The value of C in Coulomb’s law is: | 9×10^9 |
The SI unit of constant k in Coulomb’s law is: | Nm²/C² |
Two charges are located respectively at positions r1 = 3.0i and r2 = 4.0i w.r.t. a certain reference point. The distance between the charges is: | 1 |
Origin of the electric and gravitational forces: | Unknown |
The concept of electric field theory was introduced by: | Faraday |
Michael Faraday is known for his work on: | Electric |
There are two charges of 1μC and 5μC placed at a certain distance. The ratio of the forces acting on each other will be: | 1:1 |
Electric field strength is defined as: | Work |
Question | Answer |
Conventionally the angular velocity is directed at an angle of: | 90 |
If a toy car moves with a uniform speed of 2 m/sec in a circle of 0.4 m radius, its angular velocity in rev/sec is: | 0.8 |
Thirty-six degrees is equal to: | π/5 |
The relation between τ, I, and α is as follows: | τ |
If a gymnast sitting on a rotating stool with his arms outstretched brings his arms towards the chest, then its angular velocity will: | Increase |
The net force acting on a 100 kg man standing in an elevator accelerating downward with a = 0.8 m/sec² comes out to be: | 980 |
A ball tied at one end of the string is swung in a vertical circle of radius r under the action of gravity. The net force towards the center at the top must point is: | T+W |
The number of “Earth stations” which transmit signals to satellites and receive signals from them are: | 24 |
INTELSAT operates at frequencies 4, 6, 11, 14 having a unit of: | GHz |
Einstein’s theory about gravity is better than Newton’s because it gave an explanation of: | Bending |
The property of fluids due to which they resist their own flow is called: | Viscosity |
Density of a fluid is defined as: | Ratio |
Stoke’s law holds for: | Motion |
Fog droplets are suspended in air when their weight is balanced by: | Upward |
The equation of continuity is defined as Av. The unit of Av is: | Cubic |
Turbulent flow is: | Unsteady |
Unit of density to mass ratio is: | m³ |
Volume of a cylinder can be found by: | Area |
Normally, the blood pressure (torr unit) in a healthy human body varies from: | 120/80 |
Question | Answer |
When brakes are applied to a fast-moving car, the passengers will be thrown: | Forward |
The direction of acceleration of a body moving in a straight line is: | Along |
Consult page 50 of your text and tick the correct statement: | Same |
The law of conservation of linear momentum is valid for: | All |
If V denotes volume of the liquid coming out of a pipe per second, v its velocity and A as area of the pipe, then the correct formula will be: | V |
If m means mass of gases ejected per second from a rocket and v shows the change in velocity, then mv is named as: | Force |
Range of the projectile is the same for the following pair of angles: | 35 |
For maximum horizontal range, the angle of projection must be: | 45 |
At the highest point, we can claim that: | Zero |
Torque is also called: | Moment |
Work done along a closed path in a gravitational field is: | Zero |
Tick the conservative force: | Spring |
A body of weight 1 N has a kinetic energy of 1 Joule when its speed is: | 1.46 |
When two protons are brought closer, potential energy of both of them: | Increases |
The velocity given to a body to go out of the influence of Earth’s gravity is known as: | Escape |
One KWh is equal to: | 3.6 |
The consumption of energy by a 1000 W heater in half an hour is: | 0.5 |
Root out the conventional source of energy from: | Energy |
Ethanol (alcohol) is a type of: | Bio |