Physics - Online Test
Q1. permeability of a paramagnetic material is expected to decrease with increasing temperature because
Answer : Option B
Explaination / Solution:
No Explaination.
Q2. Majority current carriers in N – types are
Answer : Option D
Explaination / Solution:
The more abundant charge carriers are called majority carriers, which are primarily responsible for current transport in a piece of semiconductor. In n-type semiconductors they are electrons, while in p-type semiconductors they are holes.
Q3. A truck is coming towards you from a distance of 1000m on a straight road. At time t=0 it starts from rest. At time t=10 seconds its velocity is 20m/s. What is the average acceleration in m/
Answer : Option A
Explaination / Solution:
Average acceleration is the change in velocity divided by an elapsed time.
Initial velocity u = 0 m/s
Final velocity v = 20 m/s
Time elapsed = 10-0 = 10 s
Average acceleration
Q4. A fork of unknown frequency when sounded with another fork of frequency 256 Hz produces 4 beats/sec. The first fork is loaded with wax. It again produces 4 beats/sec. When sounded together with the fork of 256 Hz frequency, then the frequency of first tuning fork is
Answer : Option D
Explaination / Solution:
No Explaination.
Q5. A charged particle oscillates about its mean equilibrium position with a frequency of Hz. Frequency of the electromagnetic waves produced by the oscillator is
Answer : Option D
Explaination / Solution:
No Explaination.
Q6. A 1.0 m long metallic rod is rotated with an angular frequency of 400 rad about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of 0.5 T parallel to the axis exists everywhere. Emf developed between the centre and the ring is
Answer : Option D
Explaination / Solution:
e=12Bωl2=12×0.5×200×1×1=100V
Q7. In a Milikan’s oil drop apparatus an oil drop of radius 6 m and of density 0.85 kg/m3 is seen to fall freely (without any field). The velocity of drop, given viscosity of air to be 1.83 and neglecting the effect of up thrust force due to air, is
Answer : Option A
Explaination / Solution:
No Explaination.
Q8. Transmission bandwidth of fiber optic communication can be up to
Answer : Option C
Explaination / Solution:
No Explaination.
Q9. Which of the following statements not true?
Answer : Option D
Explaination / Solution:
The net acceleration of a particle in circular motion is along the radius of the circle towards the centre Only in case of uniform circular motion.
Q10. A charge q is placed at the center of the line joining two equal charges Q. The system of the three charges will be in equilibrium if q is equal to
Answer : Option D
Explaination / Solution:
Suppose in the following figure, equilibrium of charge B is considered. Hence for it's equilibrium
Suppose in the following figure, equilibrium of charge B is considered. Hence for it's equilibrium
