Answer:
A DC motor operates because the loop or the coil constantly rotates and therefore creates a torque in the presence of the magnetic field created in between two magnetic poles.
Explanation:
Working of a DC Motor
A DC motor is composed of an armature which is a current carrying coil, placed in between two opposite ends of magnets (North and south poles). This armature works as an electromagnet when places in the magnetic field of two magnet poles.
It thus, experiences a force according to the right hand rule and the torque is created with the interplay of the fixed magnetic field and the flow of current in the armature.
There are two brushes linked with two commutators that are further attached with the ends of the coils. The brushes are directly connected with the two terminals of the battery.
The work required to raise an object to a height is equal to the gravitational potential energy the object gains. <em>(C)</em>
Answer:
The magnitude of the magnetic field is
.
Explanation:
Given that,
Charge, ![q=-8.5\ \mu C=-8.5\times 10^{-6}\ C](https://tex.z-dn.net/?f=q%3D-8.5%5C%20%5Cmu%20C%3D-8.5%5Ctimes%2010%5E%7B-6%7D%5C%20C)
Speed of the charged particle, ![v=9\times 10^6\ m/s](https://tex.z-dn.net/?f=v%3D9%5Ctimes%2010%5E6%5C%20m%2Fs)
The angle between the velocity of the charge and the field is 56°.
The magnitude of force, ![F=5.9\times 10^{-3}\ N](https://tex.z-dn.net/?f=F%3D5.9%5Ctimes%2010%5E%7B-3%7D%5C%20N)
We need to find the magnitude of the magnetic field. When a charged particle moves in the magnetic field, the magnetic force is experienced by it. The force is given by :
![F=qvB\ \sin\theta](https://tex.z-dn.net/?f=F%3DqvB%5C%20%5Csin%5Ctheta)
B is the magnetic field.
![B=\dfrac{F}{qv\ \sin\theta}\\\\B=\dfrac{5.9\times 10^{-3}}{8.5\times 10^{-6}\times 9\times 10^6\ \sin(56)}\\\\B=9.3\times 10^{-5}\ T](https://tex.z-dn.net/?f=B%3D%5Cdfrac%7BF%7D%7Bqv%5C%20%5Csin%5Ctheta%7D%5C%5C%5C%5CB%3D%5Cdfrac%7B5.9%5Ctimes%2010%5E%7B-3%7D%7D%7B8.5%5Ctimes%2010%5E%7B-6%7D%5Ctimes%209%5Ctimes%2010%5E6%5C%20%5Csin%2856%29%7D%5C%5C%5C%5CB%3D9.3%5Ctimes%2010%5E%7B-5%7D%5C%20T)
So, the magnitude of the magnetic field is
. Hence, this is the required solution.
Electric current is measured in Ampere
Answer:
Increase
Explanation:
The acceleration will increase more if all the friction were removed from ramp.
Acceleration is the rate of change of velocity with time.
Frictional force is a force that opposes motion of a body.
- A large friction will reduce the velocity of a body significantly and bring it to stop, a state of no acceleration.
- When friction is removed, the acceleration of a body will increase significantly since the velocity will change rapidly.
- At each turn of time, the velocity keeps increasing due to absence of the inhibiting force of friction.