Physics - Online Test
Q1. A current is passed though two coils connected in series. The potential difference across the first coil of resistance 2 ohm is 5 volt. If the potential difference across the second coil is 12.5 volt the resistance of the second coil is
Answer : Option A
Explaination / Solution:
The current in the circuit
V1 =5 V is the p.d across the first coil of resistance R1=2Ω. The same current flows through the second coil of resistance X. . The p.d across the second coil V2 =12.5 V.
Q2. In simple harmonic motion the damping force is
Answer : Option C
Explaination / Solution:
In real oscillators, friction, or damping, slows the motion of the system. Due to frictional force, the velocity decreases in proportion to the acting frictional force.
where the c is the damping constant
Q3. Referring to the Young’s double slit experiment, Phase difference corresponding to a Path Difference of λ /3 is
Answer : Option A
Explaination / Solution:
No Explaination.
Q4. Magnetic material differences are explained by
Answer : Option D
Explaination / Solution:
No Explaination.
Q5. Escape speed from the earth is the
Answer : Option A
Explaination / Solution:
The escape velocity is the minimum velocity required to leave a planet or moon. For a rocket or other object to leave a planet, it must overcome the pull of gravity.
Vescape=11184 m/sec approximate to 11.2 km/sec
Q6. Depletion region (space charge) is formed because
Answer : Option C
Explaination / Solution:
The depletion region, also called depletion layer, depletion zone, junction region, space charge region or space charge layer, is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have been diffused away, or have been forced away by an electric field. The only elements left in the depletion region are ionized donor or acceptor impurities.
The depletion region is so named because it is formed from a conducting region by removal of all free charge carriers, leaving none to carry a current.
Q7. If the position- time graph is a straight line parallel to the time axis
Answer : Option B
Explaination / Solution:
Position-time graph of horizontal straight line parallel to time axis represents that the position of the body does not changes with the passage of time. So it represents the rest state of motion.
It means velocity of object is zero.
Q8. The speed of propagation of a sinusoidal wave is given by V=νλ where
Answer : Option D
Explaination / Solution:
No Explaination.
Q9. Food is heated in a microwave oven because
Answer : Option B
Explaination / Solution:
No Explaination.
Q10. Damping in galvanometers is based on
Answer : Option D
Explaination / Solution:
The coil of galvanometer is wound on a light metal frame. When the coil and frame rotate in the field of the permanent magnet, the eddy current set up in the frame oppose the motion so that the coil returns to zero quickly.
