Assertion: Machine parts are jammed in winter.
Reason: The viscosity of lubricant used in machine parts increase at low temperatures.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: A brass tumbler feels much colder than a wooden tray on a chilly day.
Reason: The thermal conductivity of brass is more than the thermal conductivity of wood.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: In free expansion of an ideal gas, the entropy increases.
Reason: Entropy increases in all natural processes.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: Sound waves cannot travel in vacuum but light can travel in vacuum.
Reason: Sound waves are longitudinal waves and they cannot be polarised but electromagnetic waves are transverse and they can be polarised.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
B.
If both assertion and reason are true but reason is not the correct explanation of assertion
Light is an electromagnetic wave and sound is a longitudinal and mechanical wave. In vacuum nothing is present. Sound needs either solid, liquid or gas to propagate and hence it is called a mechanical wave. Sound wave is form of energy which is transferred by vibrating air molecules if motion of propagation is air. Air molecules themselves are not energy. But light is composed of photons and photons are energy themselves. Photons can travel in any medium. Light is produced if there is any change in electric and magnetic field but sound is produced by vibrating body.
In short light itself travels from one point to another and hence do not need any medium but sound is transferred by vibrating bodies and hence need a medium to travel.
For example:- A ringing bell placed in a jar and air inside the jar is evacuated. Once air is removed from the jar, the sound of the ringing bell can no longer be heard. The clapper is seen striking the bell; but the sound that it produces cannot be heard because there are no particles inside of the jar to transport the disturbance through the vacuum.
Both the assertion and reason are correct but reason is not the correct explanation for the assertion.
With the decrease of current in the primary coil from 2 amperes to zero value in 0.01s the emf generated in the secondary coil is 1000 volts. The mutual inductance of the two coils is
1.25 H
2.50 H
5.00 H
10.00 H
What is the dimensions of impedance ?
[ M L2 T-3 A-2 ]
[ M-1 L-2 T3 A2 ]
[ M L3 T-3 A-2 ]
[ M-1 L-3 T3 A2 ]
Which wavelength of sun is used finally as electric energy?
Radio waves
Infrared waves
Visible light
visible light