Physics - Online Test
Q1. The magnetic field in a circular loop of diameter 0.1 m carrying a current of 1 A is
Answer : Option C
Explaination / Solution:
Q2.
How many meters does a vehicle moving with a speed of 18 km covers in 1 s
Answer : Option C
Explaination / Solution:
Speed of vehicle = 18 km h-1
Mean it cover 18 km in 1 hour {3600 seconds)
Distance covered in 3600 sec = 18km = 18000 m
Distance covered in 1 sec =
Q3. A power transmission line feeds input power at 2300 V to a step-down transformer with its primary windings having 4000 turns. Number of turns in the secondary in order to get output power at 230 V is
Answer : Option B
Explaination / Solution:
Np = no. of turns in primary coil = 4000
Ns = no. of turns in primary coil
Vp = input voltage = 2300 V
Vs = output voltage = 230 V
Q4. Resistance of a conductor is
Answer : Option B
Explaination / Solution:
According to Ohm’s law, V=I R. Therefore R=V/I
Q5. A spring with spring constant k when stretched through 1 cm has a potential energy U. If it is stretched by 4 cm, the potential energy will become
Answer : Option A
Explaination / Solution:
No Explaination.
Q6. For distances much greater than Fresnel distance ZF
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. the magnetic needle has magnetic moment d moment of inertia . It performs 10 complete oscillations in 6.70 s. Magnitude of the magnetic field is
Answer : Option D
Explaination / Solution:
No Explaination.
Q8. The depletion layer in the p-n junction region is caused by
Answer : Option B
Explaination / Solution:
In semiconductor physics, 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.
Q9.
The distance (s) in metres travelled by a particle is related to time (t) in seconds by the equation of motion :
S= 10t + 4t2.
What is the initial velocity of the body?
Answer : Option D
Explaination / Solution:
Velocity is given by:
v = = =
Velocity at t=0,
Q10. A boat at anchor is rocked by waves whose crests are 100 cm apart and whose velocity is 25 cm/sec. These waves reach the boat once every
Answer : Option B
Explaination / Solution:
No Explaination.
