When electrical motor isturned on,it takes longer to come up to final speed if there is a grinding wheel attached to the, shaft. Why ?

Consider the situation of block pulley arrangement shown in figure-1.63. A plank is connected to three strings and an electric motor M is fitted on to it and a string is wound on it according to the arrangement shown in figure. Given that the string is winding on shaft of motor at a speed v. Find the speed with which the plank would be going up.

A horizontal plane with the coefficient of friction k supports two bodies: a bar and an electric motor with a battery on a block. A thread attached to the bar is wound on the shaft of the electric motor. The distance between the bar and the electric motor is equal to l. When the motor is switched on, the bar, whose mass is twice as great as that of the other body, starts moving with a constant acceleration w . How soon will the bodies collide?

A fan operates at 200 volt (DC) consuming 1000W when running at full speed . It's internal wiring has resistance 1 Omega . When the fan runs at full speed , its speed becomes constant. This is because the torque due to magnetic field inside tha fan is balanced by the torque due to air resistance on the blades of the fan and torque due to friction between the fixed part and the shaft of the fan. The electrical power going into the fan is spent (i) in the internal resistance as heat, call it P_(1)(ii) in doing work against internal friction and air resistance producing heat, sound etc. call it P_(2) . When the coil of fan rotates, an emf is also induced in the coil. This opposes the external emf applied to snd the current into the fan. This emf is called back-emf,call it 'e' . Answer the following questions when the fan is running at full speed. The value of power P_(2) si

A fan operates at 200 volt (DC) consuming 1000W when running at full speed . It's internal wiring has resistance 1 Omega . When the fan runs at full speed , its speed becomes constant. This is because the torque due to magnetic field inside tha fan is balanced by the torque due to air resistance on the blades of the fan and torque due to friction between the fixed part and the shaft of the fan. The electrical power going into the fan is spent (i) in the internal resistance as heat, call it P_(1)(ii) in doing work against internal friction and air resistance producing heat, sound etc. call it P_(2) . When the coil of fan rotates, an emf is also induced in the coil. This opposes the external emf applied to snd the current into the fan. This emf is called back-emf,call it 'e' . Answer the following questions when the fan is running at full speed. The value of power P_(1) is

If you take a pail ow water and turn it upside down all the water will spell out, but if you take the pail of water, attach a rope to the handle, and turn it rapidly in a vertical circle thr water will not spill out when its is upside down at the top of the path why is this ? Explain it is terms of centrifugal force and also in terms of inertia.

An oil drop having a charge q and apparent weight W falls with a terminal speed v in absence of electric field . When electric field is switched on it starts moving up with terminal speed v. The strength of electric field is

A wheel of mass 10 kg and radius 20 cm is rotating at an angular speed of 100 rev/min when the motor is turned off. Neglecting the frictional the axle, calculate the force that must be applied tangentially to the wheel to bring it to rest in 10 revolutions.

An electric grinding wheel rotates for sometime after the power is turned off, but an electric drilling machine stops after few seconds of turning of fthe power.Why?

An electric grinding wheel rotates for sometime after the power is turned off, but an electric drilling machine stops after few seconds of turning of fthe power.Why?