If force of 6N displaces an object 2m in the direction of force, then work done will be _____
Solution
Work done is calculated using the formula \( W = F \times d \), where \( F \) is the force and \( d \) is the displacement. Here, \( W = 6N \times 2m = 12J \).
If a body of mass 1 kg is moving with velocity of 1m/sec then K.E of the body will be ________
Solution
Kinetic Energy is calculated using the formula \( KE = \frac{1}{2}mv^2 \). Here, \( KE = \frac{1}{2} \times 1kg \times (1m/s)^2 = 0.5J \).
If a machine performs 20J of work in 10sec then its power is _________
Solution
Power is calculated using the formula \( P = \frac{W}{t} \). Here, \( P = \frac{20J}{10s} = 2W \).
A body of mass 1kg is lifted through a height of 1m. The energy possessed in the body will be ________ (consider g=10m/s²)
Solution
Potential Energy is calculated using the formula \( PE = mgh \). Here, \( PE = 1kg \times 10m/s^2 \times 1m = 10J \).
The energy released during fission or fusion reaction is called _______
Solution
The energy released during fission or fusion reactions is known as nuclear energy.
Which is the renewable source of energy
Solution
Solar and wind energy are renewable sources of energy.
The ratio of output to input is called
Solution
The ratio of output to input is known as efficiency.
Work done per unit time is called _______
Solution
Work done per unit time is called power.
Coal, gas and oil are all examples of _______
Solution
Coal, gas, and oil are examples of fossil fuel energy.
_______is not a renewable source of energy.
Solution
Coal is not a renewable source of energy.
What is the formula for calculating work?
Solution
The formula for calculating work is \( W = F \times S \), where \( F \) is the force and \( S \) is the displacement.
The SI unit of energy is:
Solution
The SI unit of energy is the Joule.
Which type of energy is possessed by a moving object?
Solution
A moving object possesses kinetic energy.
Potential Energy depends on:
Solution
Potential Energy depends on mass, height, and gravity.
Which of the following is a renewable energy source?
Solution
Solar Energy is a renewable energy source.
Identify a nonrenewable energy source:
Solution
Petroleum is a nonrenewable energy source.
Efficiency is defined as the ratio of:
Solution
Efficiency is defined as the ratio of Output to Input.
Power is the work done per unit of:
Solution
Power is the work done per unit of time.
The SI unit of power is:
Solution
The SI unit of power is the Watt.
Which formula represents Kinetic Energy?
Solution
The formula for Kinetic Energy is \( \frac{1}{2}mv^2 \).
The formula for work when force acts at an angle θ to the direction of motion is:
Solution
The formula for work when force acts at an angle θ to the direction of motion is \( W = Fd \cos\theta \).
The SI unit of work is:
Solution
The SI unit of work is the Joule.
If a 50N force moves a trolley 200m at 0°, the work done is:
Solution
Work done is calculated using the formula \( W = F \times d \). Here, \( W = 50N \times 200m = 10,000J \).
Energy is best defined as:
Solution
Energy is best defined as the ability to do work.
Which is NOT a valid unit of work?
Solution
Newton is not a valid unit of work.
Work done by a force is ZERO when the angle between force and displacement is:
Solution
Work done by a force is zero when the angle between force and displacement is 90°.
What is the SI unit of kinetic energy?
Solution
The SI unit of kinetic energy is the Joule.
Kinetic energy of an object depends on:
Solution
Kinetic energy of an object depends on both mass and velocity.
The formula for kinetic energy is:
Solution
The formula for kinetic energy is \( KE = \frac{1}{2}mv^2 \).
Which of the following is an example of kinetic energy?
Solution
A flying bird is an example of kinetic energy.
A 0.4 kg ball moves at 4 m/s. What is its kinetic energy?
Solution
Kinetic Energy is calculated using the formula \( KE = \frac{1}{2}mv^2 \). Here, \( KE = \frac{1}{2} \times 0.4kg \times (4m/s)^2 = 3.2J \).
Potential energy is defined as the energy possessed by an object due to its:
Solution
Potential energy is defined as the energy possessed by an object due to its position, shape, or state.
The gravitational potential energy of an object is calculated using:
Solution
The gravitational potential energy of an object is calculated using the formula \( PE = mgh \).
A 0.05 kg ball is raised to 7 m height. If \( g = 10 \, \text{m/s}^2 \), its potential energy is:
Solution
Potential Energy is calculated using the formula \( PE = mgh \). Here, \( PE = 0.05kg \times 10m/s^2 \times 7m = 3.5J \).
Which statement about potential energy is INCORRECT?
Solution
The incorrect statement is that potential energy increases with the object’s speed. Potential energy depends on the object’s position, not its speed.
The law of conservation of energy states that energy:
Solution
The law of conservation of energy states that energy can neither be created nor destroyed.
Fossil fuels store energy in the form of:
Solution
Fossil fuels store energy in the form of chemical energy.
Hydroelectric power plants primarily rely on:
Solution
Hydroelectric power plants primarily rely on the gravitational force of water.
Which device converts solar energy directly into electricity?
Solution
Photovoltaic solar panels convert solar energy directly into electricity.
Nuclear energy is released during:
Solution
Nuclear energy is released during fission or fusion reactions.
Geothermal energy originates from:
Solution
Geothermal energy originates from Earth’s internal heat.
Wind turbines convert kinetic energy into:
Solution
Wind turbines convert kinetic energy into mechanical power.
Biomass energy is derived from:
Solution
Biomass energy is derived from organic materials like plants and garbage.
Tidal energy is produced due to gravitational forces of:
Solution
Tidal energy is produced due to gravitational forces of the Moon and sun.
Which energy source uses magma-heated water to generate electricity?
Solution
Geothermal energy uses magma-heated water to generate electricity.
A common application of wind energy in history is:
Solution
A common application of wind energy in history is grinding grain.
Ethanol and biodiesel are examples of energy derived from:
Solution
Ethanol and biodiesel are examples of energy derived from biomass.
In a nuclear power plant, steam is used to:
Solution
In a nuclear power plant, steam is used to turn turbines.
Which energy source uses reservoirs and dams?
Solution
Hydroelectric energy uses reservoirs and dams.
Sailing ships in oceans historically relied on:
Solution
Sailing ships in oceans historically relied on wind energy.
Which of the following is a renewable energy source?
Solution
Solar energy is a renewable energy source.
Which energy source does NOT produce greenhouse gas emissions?
Solution
Wind energy does not produce greenhouse gas emissions.
Which is a non-renewable energy source?
Solution
Coal is a non-renewable energy source.
Efficiency is defined as the ratio of:
Solution
Efficiency is defined as the ratio of Output to Input.
The formula for efficiency (η) is:
Solution
The formula for efficiency (η) is \( (Output/Input) × 100 \).
Why can no machine be 100% efficient?
Solution
No machine can be 100% efficient because energy is always wasted as heat, sound, or light.
What type of energy is given as input to an electric motor in a drilling machine?
Solution
Electrical energy is given as input to an electric motor in a drilling machine.
What is the unit of efficiency?
Solution
Efficiency has no unit as it is a ratio.
What is power defined as?
Solution
Power is defined as the rate of doing work.
What is the SI unit of power?
Solution
The SI unit of power is the Watt.
If a machine performs 900 J of work in 30 minutes, what is its power?
Solution
Power is calculated using the formula \( P = \frac{W}{t} \). Here, \( P = \frac{900J}{1800s} = 0.5W \).
Which conversion is correct for power units?
Solution
The correct conversion for power units is 1 hp = 746 W.
What quantity determines if a body has a power of 1 watt?
Solution
A body has a power of 1 watt if it does 1 Joule of work in 1 second.
Which statement about power is true?
Solution
Power is a scalar quantity.
Which unit is the largest?
Solution
The largest unit among the options is 1 Megawatt.
Power is calculated using the formula:
Solution
Power is calculated using the formula \( P = \frac{\text{Work}}{\text{Time}} \).