Which of the following statement is true? Rheostat, adjustable resistor used in applications that require the adjustment of current or the varying of resistance in an electric circuit.The rheostat can adjust generator characteristics, dim lights, and start or control the speed of motors.Its resistance element can be a metal wire or ribbon, carbon, or a conducting liquid, depending on the application. A rheostat is a device which is used to vary the resistance in an electrical circuit without interrupting the circuit. Commonly available resistors have a fixed value and are used for restricting smaller values of electric current.
However, the material may have large thermo-emf and a large value of temperature coefficient of resistance.But the material should meet to some special requirement such as high permissibly working temperature and low cost. The ammeter is connected in series circuit (c) The rheostat can only increase the resistance in electric circuit (d)The single key is used to switch on/off the electric circuit . The third one is not connected. In this method of speed control of three phase induction motor rheostat is added in the stator circuit due to this voltage gets dropped .In case of three phase induction motor torque produced is given by T ∝ sV 2 2. Free PDF Download of CBSE Class 10 Science Chapter 12 Electricity Multiple Choice Questions with Answers. When cells are connected in parallel the total value of the cells is the same as each individual cell. Which of the following statement is true? Assuming generators and transmission network to be lossless, the system frequency for a load of 700 MW is a) The saturation voltage V CF of silicon transistor is more than germanium transistor. b) The saturation voltage V CE for germanium transistor is more than silicon transistor. Blocked rotor test on induction motors is used to find out (a) leakage reactance (b) power factor on short circuit (c) short-circuit … It is used to control the electrical resistance of a circuit without interrupting the flow of current. Rheostats are used in dim lights to change the intensity of light. Low temperature coefficient of the resistance used for extending the range of a voltmeter (a) reduces inaccuracies due to the temperature variations (b) enables instrument to work at high temperatures (c) increases the least count of the instrument (d) enlarges the scale of reading. Magnetic Circuit; DC Generator; DC Machine; MCQ. Calculate the circuit current with the rheostat set at maximum value (1,000 ohms). Multiple Choice Question (MCQ) of Electronics page-17:241. c) The saturation voltage V CE for silicon transistor is same as that for germanium. « Back CONTENTS Next » 1. (Round the FINAL answer to three decimal places.) If we … We have Provided Electricity Class 10 Science MCQs Questions with Answers to help students understand the concept very well. Two terminal trimmers are available, although in most cases three terminal potentiometer trimmer is used as a two terminal rheostat. A rheostat is a type of variable resistor, whose resistance can be changed for varying the amount of electric current flowing through an electrical circuit. Both speed and torque can be controlled by armature voltage control, armature rheostat control, and chopper control methods. People may be most familiar with the rheostat in the form of a dimmer or slider which is used to vary the intensity of a light. Rheostat. These motors are used where the motor speed below the base speed is required as they cannot be operated above the base speed. Adding Rheostat in Stator Circuit. Rheostat is the instrument used to control the current in an electric circuit. As you can see, motor speed may be made variable using a series-connected rheostat to change total circuit resistance and limit total current. A rheostat differs from potentiometer in the respect that (A) rheostat has large number of turns (B) rheostat offers larger number of tappings (C) rheostat has lower wattage rating (D) rheostat has higher wattage ratings. The circle diagram for an induction motor cannot be used to determine (a) efficiency (b) power factor (c) frequency (d) output Ans: a. The rheostat which is used to vary the resistance per phase causes unbalancing in rotor. Which of the following theorem is used for the analysis of a transistor circuit (a) Thevenin’s theorem. Dec 10,2020 - The rheostat is used in the circuit to :a)increase the magnitude of current onlyb)decrease the magnitude of current onlyc)increase or decrease the magnitude of currentd)none of theseCorrect answer is option 'C'. In its simplest configuration, a potentiometer may be used as a rheostat by simply using the wiper terminal and one of the other terminals, the third terminal left unconnected and unused: Free PDF Download - Best collection of CBSE topper Notes, Important Questions, Sample papers and NCERT Solutions for CBSE Class 10 Physics Electricity. It has several applications in both DC and AC circuits. 1․ A power system has three synchronous generators. (b) Superposition theorem. | EduRev Class 10 Question is disucussed on EduRev Study Group by 170 Class 10 Students. Check the below NCERT MCQ Questions for Class 10 Science Chapter 12 Electricity with Answers Pdf free download. As shown, the electricity must first flow through the HOA switch before it can energize the coil of the motor contactor. Rheostat is generally used in the applications where high voltage or current is required. It is most often designed with a ceramic core. Rheostat has 3 terminals and usually consist of a resistive wire wrapped to form a toroid coil with a wiper that slides along the surface of the coil. 76. In a rheostat, only two lead terminals (One fixed and one moving) are connected to the circuit. Class 10 Science MCQs Chapter 12 […] Generally, the term potentiometer is used to represent a three-terminal variable resistor. MCQ Questions for Class 10 Science with Answers were prepared based on the latest exam pattern. Potentiometer (POT) With all three terminals connected to the circuit, pots are generally used … Preset Rheostat: When rheostats are used in a printed circuit board, they are used as trimmers or preset rheostats. (d) Reciprocity. Test the rheostat in this condition for an hour and check that there is no deterioration of wire or Published by Houghton Mifflin Harcourt Publishing Company. In case of a large machine the size of the rheostat will be large and in such case it is not easily portable. of the rheostat till the ammeter reads the also be marked on packaging of rheostat. Rheostat is used for varying higher values of electric current. * Resistance can varied in a circuit without the interruption so as to control the current. Take the quiz to find out! Rheostat: A component used to regulate the electric current flowing through a circuit without changing the voltage is called Rheostat. Sliding the movable contact, the resistance between terminals can be varied. c) The saturation voltage V CE for silicon transistor is same as that for germanium. When it is used in a control circuit, it looks like Figure 3-18. 8.2 Marking on Packaging The requirements for marking specified at 7 shall IS 8622 : 1999 marked current of the rheostat. Click here to refresh Mechanical Engineering; Electrical Engineering; Electronics Engineering; Civil Engineering; Top. Science Lab Manual Class 10 Experiment – 1. Trimmers are nothing but a small rheostat, mostly used in calibration circuits. If you have any query regarding CBSE Class 10 Science Chapter 12 Electricity Multiple Choice Questions with Answers, drop a comment below and we will get back to you at the earliest. To get through the switch, the switch must be in the hand or auto position. Multiple Choice Question (MCQ) of Electronics page-17:241. In this post, you'll learn the 3 essential differences between both. (c) Norton’s theorem. It requires more maintenance, hence the cost associated with it is more. Brief History It is used to change the resistance in the circuit. a) The saturation voltage V CF of silicon transistor is more than germanium transistor. The unit is volts (V). Rheostat is an adjustable or variable resistor. Your name: Your email: Your Comments: Enter the code above here : Can't read the image? The resistances generate huge losses and generate heat in the system. Its main property is it is a power consuming element, and opposes the flow of current. * Rheostat is a variable resistance which is used in the circuit to control the current. rheostat (rē`əstăt'), device whose resistance to electric current depends on the position of some mechanical element or control in the device.Typically a rheostat consists of a resistance element equipped with two contacts, or terminals, by which it is attached to a circuit: a fixed contact at one end and a sliding contact that can be moved along the resistance element. Voltage vs Current We hope the given MCQ Questions for Class 10 Science Electricity with Answers will help you. The turbine-governor characteristics corresponding to the generators are P 1 =50(50 − f), P 2 = 100(51 − f), P 3 = 150(52 − f) Where, f denotes the system frequency in Hz, and P 1, P 2, P 3 are the power outputs of the turbines in MW. - 823449 A rheostat differs from potentiometer in the respect that, (B) rheostat offers larger number of tappings, Submit your documents and get free Plagiarism report, Your solution is just a click away! In technical terms, the potentiometer and rheostat represent two different configurations in which a variable resistor can be used. The entire NCERT textbook questions have been solved by best teachers for you. If we increase the resistance of the rheostat, the flow of electric current through the light bulb decreases. For two 1.5 V cells in parallel, the voltage stays at 1.5 V, but the life (current capacity) of the battery is doubled. It has variable resistance. Can you explain this answer? The most common way to vary the resistance in a circuit is to use a rheostat. While the rheostat is a two terminal device that forms connection with one end and the wiper or slider only. 77. It is used to control the electrical resistance of a circuit without interrupting the flow of current. 3. The following circuit contains two resistors. Enter Your Suggestion/Comments Here. MCQ OF ELECTRICITY . Resistance is a passive element in electrical and electronic circuits. One is a fixed value resistor, but the other is a variable resistor which is being used as a rheostat. Aim

Another way to prevent getting this page in the future is to use Privacy Pass. • If a parallel circuit is opened in the main line, the current, (a) increases in the branch of the lowest resistance, (d) is zero in the highest resistive branch, 11. 5. MCQ Questions for Class 10 Science with Answers was Prepared Based on Latest Exam Pattern. The word rheostat was coined about 1845 by Sir Charles Wheatstone , from the Greek ῥέος rheos meaning "stream", and - στάτης - states (from ἱστάναι histanai , " to set, to cause to stand") meaning "setter, regulating device", [6] [7] [8] which is a two-terminal variable resistor. It is always connected in parallel in the circuit. In a parallel circuit there is more than one path for the current to flow along. b) The saturation voltage V CE for germanium transistor is more than silicon transistor. Students can solve NCERT Class 10 Science Electricity Multiple Choice Questions with Answers to know their preparation level.

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