Physics-
General
Easy
Question
An electric motor runs a DC source of emf 200V and draws a current of 10A. If the efficiency is 40%, then the resistance of the armature is
- 5
- 12
- 120
- 160
The correct answer is: 12
Here, 
But
Related Questions to study
Physics-
The square root of the product of inductance and capacitance has the dimension of
The square root of the product of inductance and capacitance has the dimension of
Physics-General
Physics-
The current in a 
circuit builds up to 3/4th of its steady state value in 4
. The time constant of this circuit is
The current in a circuit builds up to 3/4th of its steady state value in 4. The time constant of this circuit is
Physics-General
Physics-
A conducting rod of length l is moving in a transverse magnetic field of strength B with velocity v. The resistance of the rod is R. the current in the rod is
A conducting rod of length l is moving in a transverse magnetic field of strength B with velocity v. The resistance of the rod is R. the current in the rod is
Physics-General
Physics-
A copper rod of length 
is rotated about one end perpendicular to the magnetic field 
with constant angular velocity 
. The induced e.m.f. between the two ends is
A copper rod of length is rotated about one end perpendicular to the magnetic field with constant angular velocity . The induced e.m.f. between the two ends is
Physics-General
Physics-
Turn ratio is 1.25. The step up transformer operates at 230 V and current through secondary is 2 A. Then current in primary is
Turn ratio is 1.25. The step up transformer operates at 230 V and current through secondary is 2 A. Then current in primary is
Physics-General
Physics-
Faraday’s laws are consequence of conservation of
Faraday’s laws are consequence of conservation of
Physics-General
Physics-
A coil of area 
has 500 turns. Magnetic field of 
is perpendicular to the coil. The field is reduced to zero in 
. The induced e.m.f in the coil is
A coil of area has 500 turns. Magnetic field of is perpendicular to the coil. The field is reduced to zero in . The induced e.m.f in the coil is
Physics-General
Physics-
A particle moves in a plane with constant acceleration in a direction different from the initial velocity. The path of the particle will be
A particle moves in a plane with constant acceleration in a direction different from the initial velocity. The path of the particle will be
Physics-General
Physics-
At the top of the trajectory of a projectile, the direction of its velocity and acceleration are
At the top of the trajectory of a projectile, the direction of its velocity and acceleration are
Physics-General
Physics-
If a cyclist moving with a speed of 4.9 
on a level road can take a sharp circular turn of radius 4 
then coefficient of friction between the cycle tyres and road is
If a cyclist moving with a speed of 4.9 on a level road can take a sharp circular turn of radius 4 then coefficient of friction between the cycle tyres and road is
Physics-General
Physics-
A chain of 125 links is 1.25 m long and has mass of 2 kg with the ends fastened together. It is set for rotating at 50 
, centripetal force on each links is
A chain of 125 links is 1.25 m long and has mass of 2 kg with the ends fastened together. It is set for rotating at 50 , centripetal force on each links is
Physics-General
Physics-
A piece of marble is projected from earth’s surface with velocity of 
. 2 s later, it just clears a wall 5 m high. What is the angle of projection?
A piece of marble is projected from earth’s surface with velocity of . 2 s later, it just clears a wall 5 m high. What is the angle of projection?
Physics-General
Physics-
Radius of the curved road on national highway is 
Width of the road is 
The outer edge of the road is raised by 
with respect to inner edge so that a car with velocity 
can pass safe over it. The value of is
Radius of the curved road on national highway is Width of the road is The outer edge of the road is raised by with respect to inner edge so that a car with velocity can pass safe over it. The value of is
Physics-General
Physics-
A frictionless track 
ends in a circular loop of radius 
figure. A body slides down the track from point 
which is at a height 
cm. Maximum value of 
for the body to successfully complete the loop is
A frictionless track ends in a circular loop of radius figure. A body slides down the track from point which is at a height cm. Maximum value of for the body to successfully complete the loop isPhysics-General
Physics-General
Physics-
If a body is projected with an angle 
to the horizontal then
If a body is projected with an angle to the horizontal then
Physics-General
