Options (b) and (d) are correct about an electric motor.
An electric motor is a device which coverts electrical energy into mechanical energy.It works on the principle that when a current carrying coil is placed in a magnetic field, it experiences torque. Because of that torque, the coil rotates and thus the electrical energy gets converted into mechanical (motion) energy.
Answer:
A. F=107.6nN
B. Repulsive
Explanation:
According to coulombs law, the force between two charges is express as
F=(Kq1q2) /r^2
If the charges are of similar charge the force will be repulsive and if they are dislike charges, force will be attractive.
Note the constant K has a value 9*10^9
Hence for a charge q1=7.10nC=7.10*10^-9, q2=4.42*10^-9 and the distance r=1.62m
If we substitute values we have
F=[(9×10^9) ×(7.10×10^-9) ×(4.42×10^-9)] /(1.62^2)
F=(282.4×10^-9)/2.6244
F=107.6×10^-9N
F=107.6nN
B. Since the charges are both positive, the force is repulsive
Answer:
Elastic potential energy, 
Explanation:
Charge, 
Potential, V = 50 V
It is required to find the electric potential energy in a capacitor stored in it. The formula of the electric potential energy in a capacitor is given by :
So, the electric potential energy stored in the capacitor is 
Answer:
Intensive properties
Density
Color
temperature
Melting point
Extensive properties
Mass
Volume
Total Energy
Explanation:
Intensive properties: In Physics, Intensive properties which are not depend of the amount of matter in a sample, It only depends of the type of matter, some examples of intensive properties are:
1. Density: It is a intensive property. It can explain better with a example: the water density is 1000 kg/m3, So if we have 1 liter or 1000 liters of water the density will be the same for the two samples.
2. Color: Solid sodium chloride is white. If you have 2 samples the first recipient with 2 kilograms of NaCl and the second with 10 kilograms of NaCl. The color of the substance does not depend on the amount of the substance.
As was mentioned before the same theory is applied to temperature and melting point concepts.
On the other hand,
Extensive properties are properties of the matter which depend on the amount of matter that is present in the system or sample. some examples are:
1. Mass: It is a property that measures the amount of matter that an object contains. For example, 10 kilograms of solid Copper contains a higher mass than 2 kilograms of the same metal.
2. Volume: It is a property which measures the space occupied by an object or a substance. For example, the space occupied by a glass of milk is lower than the space occupied by a bottle of milk, Then the volume of the glass of milk is lower than the volume of the bottle of milk.
3. Finally the total energy is contained in molecules and atoms that constituted systems so, if the amount of matter increases the number of molecules too, then the total energy will increase.
I hope it helps you.
Answer:
Explanation:
Given that
Mass of rifle = M
Initial velocity ,u= 0
Mass of bullet = m
velocity of bullet = v
Lets take final speed of the rifle is V
There is no any external force ,that is why linear momentum of the system will be conserve.
Initial linear momentum = Final linear momentum
M x 0 + m x 0 = M x V + m v
0 = M x V + m v
Negative sign indicates that ,the recoil velocity will be opposite to the direction of bullet velocity.
