Electrical energy is used to run the fan
Here as per given condition 750 J of electrical energy is used to run the fan which is converted into Kinetic energy as 400 J
So here we can see that 350 J of energy is lost against many other type of frictional and resistive loses.
So here we can say that out of 750 J of energy only 400 J is used to run the fan and rest amount of energy is lost against friction.
also we can say that efficiency of this fan will be



Answer:
Option E
Explanation:
In the presence of two point charges at the two vertices of an equilateral triangle, the resultant electric field at the third vertex due to these charges can not be zero whether the charges are identical or not.
The reason being that only of the x or y component of the field can be cancelled out in either case still the total field can't be reduced to zero.
This can only be achieved if another charge is present.
I would say mass, and weight.
Answer:
v = 7.69 x 10³ m/s = 7690 m/s
T = 5500 s = 91.67 min = 1.53 h
Explanation:
In order for the satellite to orbit the earth, the force of gravitation on satellite must be equal to the centripetal force acting on it:

where,
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
Me = Mass of Earth = 5.97 x 10²⁴ kg
r = distance between the center of Earth and Satellite = Radius of Earth + Altitude = 6.371 x 10⁶ m + 0.361 x 10⁶ m = 6.732 x 10⁶ m
v = orbital speed = ?
Therefore,

<u>v = 7.69 x 10³ m/s</u>
For time period satellite completes one revolution around the earth. It means that the distance covered by satellite is equal to circumference of circle at the given altitude.
So, its orbital speed can be given as:

where,
T = Time Period of Satellite = ?
Therefore,

<u>T = 5500 s = 91.67 min = 1.53 h</u>