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
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
In the following diagram, which particle has highest e/m value?
A
B
C
D
D.
D
When electron enters a region in which there is uniform magnetic field perpendicular to the velocity v, of the electric field, the electron experiences a force F with a magnitude given by following eqaution
F = e v B
The force is perpendicular to both v and B and its direction can be found by using the right-hand rule. The force will cause the electron to circular orbit with radius r ( uniform circular motion ).
We can equate the forces on the electron
⇒ e v B =
, if B and v are the same. The radius of curvature of D is minimum. Therefore is maximum.
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