Which one of the following statements is correct?
Any energy transfer that does not involve temperature difference in some way is not heat.
Any energy transfer always requires a temperature difference.
On heating the length and volume of the object remain exactly the same.
Whenever there is a temperature difference, heat is the only way of energy transfer.
If T is the time period of an oscillating pendulum, which one of the following statements is NOT correct?
The motion repeats after time T only once
T is the least time after which motion repeats itself
The motion repeats itself after nT, where n is a positive integer
T remains the same only for small angular displacements
If an object moves with constant velocity, then which one of the following statements is NOT correct?
Its motion is along a straight line
Its speed changes with time
Its acceleration is zero
Its displacement increases linearly with time
An object is moving with uniform acceleration a. Its initial velocity is u and after time t its velocity is v. The equation of its motion is v = u + at. The velocity (along y-axis) time (along x-axis) graph shall be a straight line
passing through origin
with x-intercept u
with y-intercept u
with slope u
What is the net force experienced by a bar magnet plated in a uniform magnetic field?
Zero
Depends upon length of the magnet
Never zero
Depends upon temperature
Which one of the following has maximum inertia?
An atom
A molecule
A one-rupee coin
A cricket ball
Which one of the following is the value of 1 kWh of energy converted into joules?
1.8 x 106 J
3.6 x 106 J
6.0 x 106 J
7.2 x 106 J
Which one of the following statements about gravitational force is NOT correct?
It is experienced by all bodies in the universe
It is a dominant force between celestial bodies
It is a negligible force for atoms
It is same for all pairs of bodies in our universe
Whether an object will float or sink in a liquid, depends on
mass of the object only
mass of the object and density of liquid only
difference in the densities of the object and liquid
mass and shape of the object only
Which one of the following devices is non-ohmic?
Conducting copper coil
Electric heating coil
Semi conductor diode
Rheostat
C.
Semi conductor diode
The device that does not follow ohm's law is known as a non-ohmic device (i.e., the resistance is different for different currents passing through it).