# If the motor is overloaded, then the magnitude of ‘back emf’” a. Increases b. Decreases c. Constant d. Becomes zero

If the motor is overloaded, then the magnitude of ‘back emf’”
a. Increases b. Decreases c. Constant d. Becomes zero

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a. Increases

Increases

Decrease

## Related Questions

When a motor is just started, back emf is almost ______: a. Infinite b. zero c. minimum d. maximum In the plane of AC generator coil is parallel to the field, then emf induced in coil is: a. maximum b. minimum c. zero d. intermediate In the plane of the A.C generator coil is perpendicular to the field, then induced emf in the coil is: a. Maximum b. minimum c. zero d. intermediate value If velocity of a conductor moving through a magnetic field ‘B’ is made zero, then Motional emf will be: a. –VBL b. –V/BL c. – BL/V d. zero In an oil-lubricated journal bearing, coefficient of friction between the journal and the bearing. [IES-1995] (a) Remains constant at all speeds. (b) is minimum at zero speed and increases ... speed. (d) becomes minimum at an optimum speed and then increases with further increase in speed.
Last Answer : (d) becomes minimum at an optimum speed and then increases with further increase in speed. A wire loop is moved parallel to a uniform magnetic field. The induced emf in the loop: a. depends on the shape b. depends on area c. depends on nature of loop d. zero Terminal potential difference of a battery is greater than its emf when a. the internal resistance of battery is infinite b. the internal resistance of battery is zero c. the battery is charged d. the battery is discharged
Last Answer : c. the battery is charged The induced emf is produced in a circuit due to: a. Initial magnetic flux b. final magnetic flux c. Change of magnetic flux d. constant magnetic flux
Last Answer : d. constant magnetic flux When two gases are mixed, the entroру (a) Remains constant (b) Decreases (c) Increases (d) Becomes zero When water freezes its density – (1) Decreases (2) Becomes Zero (3) Remains constant (4) Increases
Last Answer : (1) Decreases Explanation: Water at ordinary temperatures contracts and in-creases in density as it is cooled, like most substances. But at about 4°C it reaches a maximum density and then decreases in density as it approaches the freezing point. This is referred to as anomalous property of water. By increasing the current, the drift velocity A. decreases B. increases C. remains constant D. becomes zero As the ball falls towards the ground, its velocity A. increases B. decreases C. remains constant D. becomes zero When water freezes its density (1) Decreases (2) Becomes Zero (3) Remains constant (4) Increases A wire of uniform area of cross-section A length L and resistance R is cut into two parts. Resistivity of each part a. remains the same b. is doubled c. is halved d. becomes zero
Last Answer : a. remains the same With increase in temperature, the thermal conductivity of most liquids (A) Increases (B) Decreases (C) Remain same (D) First increases upto a certain temperature and then becomes constant
Last Answer : (C) Remain same On increasing the reverse bias to a large value in a p-n junction diode current (a) Increases slowly (b) Remains fixed (c) Suddenly increases (d) Decreases slowly
Last Answer : (c) Suddenly increases In forward bias, the width of potential barrier __________ (a) Increases (b) decreases (c) remains same (d) no effect The direction of induced EMF can be found with the help of - The induced emf in a coil depends upon: a. Strength of magnetic field b. Resistance of the coil c. area of the coil d. All of them
Last Answer : d. All of them Which of the following will produce an induced emf: a. Changing area of coil b. Changing magnetic flux c. changing orientation of coil d. all of them
Last Answer : c. changing orientation of coil The phenomena of induced emf was observed by Faraday and Henry in: a. 1931 b. 1831 c. 1535 d. 1940 The phenomenon of producing emf in the coil due to change of current in the coil itself is called: a. mutual induction b. self-induction c. self-inductance d. mutual inductance
Last Answer : d. mutual inductance The current flowing in a coil due to induced emf depends upon: a. shape of coil b. resistance of coil c. area of coil d. magnetic flux
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Last Answer : (1) Increases Explanation: The temperature stays the same until all the liquid has vaporized. As the temperature of a liquid rises, the pressure of escaping vapor also rises, and at the boiling point ... vapor is equal to that exerted on the liquid by the surrounding air, causing bubbles to form. With the increase of pressure, the boiling point of any substance – (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero
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Last Answer : (2) decreases Explanation: In the solid and liquid phase, water molecules are bonded to each other by virtue of an interaction between hydrogen atoms on one molecule and the oxygen atom of another - the process ... to as "hydrogen bonding." The result is a kind of "skin" on liquid water's surface. .If we narrow the distance between two slits in Young’s experiment the fringes width __________. A. Increases B. Decreases C. Remains same D. becomes zero The surface tension of water on adding detergent to it (1) increases (2) decreases (3) no change (4) becomes zero Thevelocityfactor of a transmissionline a. depends on the dielectric constant of the material used b. increases the velocity along the transmission line c. is govern by the skin effect d. is higher for a solid dielectric than for air
Last Answer : a. depends on the dielectric constant of the material used If magnetic field is doubled then magnetic energy density becomes: a. Four times b. Two times c. Three times d. Six times
Last Answer : c. Three times A solenoid has n turns and length l. If length is reduced to l/2 and turns are doubled then magnetic field B produced by it becomes equal to a) 2B b) 4B c) 1/2 B d) None of these A proton moves in a uniform magnetic field in a circular path of radius R. If the energy of proton is doubled then the new radius becomes a) R √2 b) 2R c) R 2 d) √2 R
Last Answer : d) √2 R Two electron beams move parallel to each other. The nature of force between them is a) Attractive b) Repulsive c) Dependent on magnitude of velocity d) None When a detergent is added to pure water, its surface tension – (1) increases (2) decreases (3) remains constant (4) becomes infinite
Last Answer : (2) decreases Explanation: When Soaps and detergents are added to water, they weaken the strength of the skin on the water's surface due to surface tension by interfering with hydrogen bonding ... of the soap or detergent is also attracted to the water, thereby decreasing the surface tension. When a catalyst increases the rate of forward reaction, the value of rate constant (A) Increases (B) Decreases (C) Remain same (D) Becomes infinite When a detergent is added to pure water, its surface tension (1) increases (2) decreases (3) remains constant (4) becomes infinite An ideal gas is compressed in a cylinder so well insulated that there is essentially no heat transfer. The temperature of gas  a. Remains constant  b. increases  c. decreases  d. is basically zero The termcritical angle describes a. the point at which light is refracted b. the point at which light becomes invisible c. the point at which light has gone from the refractive mode to the reflective mode d. the point at which light has crossed the boundary layers from one index to another
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