Physics-
General
Easy
Question
Work of electric motor is
- To convert ac into dc
- To convert dc into ac
- Both [a] and [b]
- To convert ac into mechanical work
The correct answer is: To convert ac into mechanical work
Related Questions to study
Physics-
A boy playing on the roof of a 10 m high building throws a ball with a speed of 
at an angle of 30
with the horizontal. How far from the throwing point will the ball be at the height of 10 m from the ground? 
A boy playing on the roof of a 10 m high building throws a ball with a speed of at an angle of 30 with the horizontal. How far from the throwing point will the ball be at the height of 10 m from the ground?
Physics-General
Physics-
A vector 
when added to the vector 
=
yields a resultant vector that is in the positive 
direction and has a magnitude equal to that of . Find the magnitude of
A vector when added to the vector = yields a resultant vector that is in the positive direction and has a magnitude equal to that of . Find the magnitude of
Physics-General
Physics-
The simple sum of two co-initial vectors is 10 units. Their vector sum is 8 units. The resultant of the vectors is perpendicular to the smaller vector. The magnitudes of the two vectors are
The simple sum of two co-initial vectors is 10 units. Their vector sum is 8 units. The resultant of the vectors is perpendicular to the smaller vector. The magnitudes of the two vectors are
Physics-General
Physics-
In an atom for the electron to revolve around the nucleus, the necessary centripetal force is obtained from the following force exerted by the nucleus on the electron
In an atom for the electron to revolve around the nucleus, the necessary centripetal force is obtained from the following force exerted by the nucleus on the electron
Physics-General
Physics-
A wheel completes 2000 revolutions to cover the 
distance. Then the diameter of the wheel is
A wheel completes 2000 revolutions to cover the distance. Then the diameter of the wheel is
Physics-General
Physics-
For a body moving in a circular path, a condition for no skidding if 
is the coefficient of friction, is
For a body moving in a circular path, a condition for no skidding if is the coefficient of friction, is
Physics-General
Physics-
A stone tied to a string of length 
is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position and has speed 
. The magnitude of the change in its velocity as it reaches a position where the string is horizontal is
A stone tied to a string of length is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position and has speed . The magnitude of the change in its velocity as it reaches a position where the string is horizontal is
Physics-General
Physics-
If a particle covers half the circle of radius 
with constant speed then
If a particle covers half the circle of radius with constant speed then
Physics-General
Physics-
A mass of 
is whirled in a horizontal circle by means of a string at an initial speed of 5 
Keeping the radius constant the tension in the string is doubled. The new speed is nearly
A mass of is whirled in a horizontal circle by means of a string at an initial speed of 5 Keeping the radius constant the tension in the string is doubled. The new speed is nearly
Physics-General
Physics-
A cricketer can throw a ball to a maximum horizontal distance of 
. The speed with which he throws the ball is (to the nearest integer)
A cricketer can throw a ball to a maximum horizontal distance of . The speed with which he throws the ball is (to the nearest integer)
Physics-General
Physics-
Two bodies are projected from the same point with equal speeds in such directions that they both strike the same point on a plane whose inclination is
. If 
be the angle of projection of the first body with the horizontal the ratio of their times of flight is
Two bodies are projected from the same point with equal speeds in such directions that they both strike the same point on a plane whose inclination is. If be the angle of projection of the first body with the horizontal the ratio of their times of flight is
Physics-General
Physics-
A projectile is thrown at angle with vertical. It reaches a maximum height H. The time taken to reach the highest point of its path is
A projectile is thrown at angle with vertical. It reaches a maximum height H. The time taken to reach the highest point of its path is
Physics-General
Physics-
A particle is moving with velocity 
where 
is a constant. The general equation for its path is
A particle is moving with velocity where is a constant. The general equation for its path is
Physics-General
Physics-
The force required to keep a body in uniform circular motion is
The force required to keep a body in uniform circular motion is
Physics-General
Physics-
An aeroplane moving horizontally at a speed of 
and at a height of 
is to drop a bomb on a target. At what horizontal distance from the target should the bomb be released
An aeroplane moving horizontally at a speed of and at a height of is to drop a bomb on a target. At what horizontal distance from the target should the bomb be released
Physics-General
