Description : If a copper wire is increased to double its length, its resistance will become (1) four times (2) one–fourth (3) double (4) half

**Answer** : double

**Answer** : Resistance of a wire is r ohms. The wire is stretched to double its length, then its resistance in ohms is 4 r.

Description : Indicate the false statement about the resistance of a wire (1) it depends on material of wire (2) it is directly proportional to the length of wire (3) it is directly proportional to the area of cross-section of wire (4) resistance of metallic wire increases with increase in temperature

**Answer** : it is directly proportional to the area of cross-section of wire

Description : If a wire of resistance R is melted and recast to half of its length, then the new resistance of the wire will be

**Answer** : R/4

Description : What happens to the resistance of a wire when its length as well as the cross-sectional area are doubled? A) It doubles B) It becomes 4 times C) It becomes 2π times D) It remains the same

**Answer** : Automatically the resistivity will increase as they are the factors affecting the resistivity

**Answer** : A wire of resistance R has it length and cross-section both doubled. Its resistance will become R.

Description : Resistance of a copper wire decreases when ......................increases

**Answer** : Resistance of a copper wire decreases when diameter increases

Description : If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes?

**Answer** : If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes 0.4 ohm.

Description : If Poisson's ratio of a resistance wire strain gauge is 1.8, then neglecting piezo-resistive effects, its Gauge factor is : (A) 2.8 (B) 2.6 (C) 4.6 (D) 3.6

**Answer** : If Poisson's ratio of a resistance wire strain gauge is 1.8, then neglecting piezo-resistive effects, its Gauge factor is : 4.6

Description : When number of turns in a coil is trippled, without any change in the length of coil, its self inductance becomes? (1) Nine times (2) Three times (3) Six times (4) One–third

**Answer** : Nine times

Description : A wire of resistance R is cut into ‘n’ equal parts. These parts are then connected in parallel. The equivalent resistance of the combination will be

**Answer** : R/n2

Description : When a dipole antenna of 1/8 length has an equivalent total resistance of 1.5 Watt then the efficiency of the antenna is (A) 0.89159% (B) 8.9159% (C) 89.159% (D) 891.59%

**Answer** : When a dipole antenna of 1/8 length has an equivalent total resistance of 1.5 Watt then the efficiency of the antenna is 89.159%

Description : After a projectile is fired horizontally near the earth's surface, the horizontal component of its velocity, neglecting any air resistance: w) increases steadily x) decreases steadily y) first decreases, then increases z) remains constant

**Answer** : ANSWER: Z -- REMAINS CONSTANT

Description : Consider three CPU intensive processes P1, P2, P3 which require 20, 10 and 30 units of time, arrive at times 1, 3 and 7 respectively. Suppose operating system is implementing Shortest Remaining Time first (preemptive scheduling) ... end of Ready queue are not counted). (A) 3 (B) 2 (C) 4 (D) 5

**Answer** : (A) 3

Description : An outgoing batch of students wants to gift a PA system worth Rs 4,200 to their school. If the teachers, offer to pay 50% more than the students and an external benefactor gives three times the teacher's contribution, then ... the teachers donate? A) Rs 600 B) Rs 840 C) Rs 900 D) Rs 1,200 E) NONE

**Answer** : Answer: C The ratio of the share students : teacher: benefactor=1:1.5 : 4.5 So the proportion to teacher's share = 1.5/7 Hence, the teachers would donate 1.5/7×4200=Rs 900

Description : Three active partners A, B, C start a work. Twice of A's capital is equal to 6 times of B's capital is nine times C's capital. If B's profit is Rs. 7500. Then find the total profit. a) 30750 b) 30833 c) 45250 d) 32745

**Answer** : Answer: B) The capital of C be y. The capital of B be 9y. The capital of A be 54y/2 = 27y Ratio of A:B:C =27y:9y:y Total =7500/9*37=Rs 30833.

Description : A copper wire of length l and diameter d has potential difference V applied at its two ends. The drift velocity is vd . If the diameter of wire is made d/3, then drift velocity becomes

**Answer** : A copper wire of length l and diameter d has potential difference V applied at its two ends. The drift velocity is vd . If the diameter of wire is made d/3, then drift velocity becomes vd.

Description : What is the resistance of a 160 m wire with a uniform diameter of 0.28 mm, if the specific resistance is 12.32 μΩ-cm? A) 3.2 Ω B) 3.2 μΩ C) 0.8 Ω D) None of these

**Answer** : What is the resistance of a 160 m wire with a uniform diameter of 0.28 mm, if the specific resistance is 12.32 μΩ-cm? A) 3.2 Ω B) 3.2 μΩ C) 0.8 Ω D) None of these

Description : What is resistance wire made of?

**Answer** : Resistance wire is made up of Nichrome .

Description : What happens to the resistance when the current increases?

**Answer** : Resistance reduces when current increases.

Description : A magnetic circuit has effective iron length of 100 cm and it is wound with 800 turns of wire carries 1 A. Find the magnetic field strength.

**Answer** : magnetic field strength

Description : A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span?

**Answer** : A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span 4.0 cm.

Description : A drawn wire of resistance 5 Ω is further drawn so that its diameter becomes one-fifth of the original. What is its resistance with volume remaining the same ? (a) 25 Ω (b) 125 Ω (c) 625 Ω (d) 3125 Ω

**Answer** : A drawn wire of resistance 5 Ω is further drawn so that its diameter becomes one-fifth of the original. What is its resistance with volume remaining the same ? (a) 25 Ω (b) 125 Ω (c) 625 Ω (d) 3125 Ω

Description : A nichrome wire used as heater coil has the resistance of 1 ohm/m. For a heater of 1000 W at 200 V, the length of wire required will be

**Answer** : A nichrome wire used as heater coil has the resistance of 1 ohm/m. For a heater of 1000 W at 200 V, the length of wire required will be 40 m.

**Answer** : A wire of 0.14 mm diameter and specific resistance 9.6 micro-ohm-cm is 440 cm long. The resistance of the wire will be 27.4 ohm.

Description : Describe the importance of three wire and four wire configuration for RTD with suitable circuit diagram.

**Answer** : Three wire RTD: Four wire RTD: Three wire configurations is used to help the circuit compensate for lead wire resistance, and thus provide a truer indication of the measured ... the leads. To get the optimum performance, it is generally best to specify the RTD configuration.

Description : Differentiate between two and three wire control.

**Answer** : Two wire control: Three wire control It provides low voltage release It provides low voltage protection IT will automatically start when power resumes IT will ... located at remote locations Its is used for industrial control panels where safety is important

Description : In a three phase half wave rectifier feeding resistive load, if the input source is a three phase 4 wire system and line to line voltage is 100 V. The supply frequency is 400 Hz. The ripple frequency at the output is: (1) 400 Hz (2) 800 Hz (3) 1200 Hz (4) None of these

**Answer** : In a three phase half wave rectifier feeding resistive load, if the input source is a three phase 4 wire system and line to line voltage is 100 V. The supply frequency is 400 Hz. The ripple frequency at the output is: 1200 Hz

Description : In a 3-phase 4-wire distribution system three unbalanced but equal magnitude impedances are connected between respective lines and neutral. The magnitude of current in the neutral conductor for RYB and RBY phase sequences ... ) zero (B) same (C) different (D) same in magnitude but differs in phase.

**Answer** : In a 3-phase 4-wire distribution system three unbalanced but equal magnitude impedances are connected between respective lines and neutral. The magnitude of current in the neutral conductor for RYB and RBY phase sequences are different

Description : In a certain three -wire Y -connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages will be: A. 2,000 V B. 6,000 V C. 666 V D. 3,464 V

**Answer** : In a certain three -wire Y -connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages will be: 3,464 V

Description : Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be?

**Answer** : Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be 10 ohms.

Description : Two heater wires of equal length are connected first in series and then in parallel. The ratio of heat generated from series to parallel connection will be (a) 4 : 1 (b) 2 : 1 (c) 1 : 2 (d) 1 : 4

Description : The hot resistance of a tungsten lamp is about 10 times the cold resistance. Accordingly, cold resistance of a 100 W, 200 V lamp will be

**Answer** : The hot resistance of a tungsten lamp is about 10 times the cold resistance. Accordingly, cold resistance of a 100 W, 200 V lamp will be 40 ohm.

Description : If the diameter of the current carrying conductor increases then the corona loss (a) increases (b) decreases (c) remains unchanged (d) none of these

Description : When alternator excitation increases and machine is operating at lagging power factor then (A) Armature current increases (B) Armature current decreases (C) Armature current remains unchanged (D) Armature voltage remains unchanged

Description : if voltage is 230 Volts , frequency is 50 Hz and current is 1 ampere then what will be the resistance?

**Answer** : As V = 230v and I = 1A Therfore by ohm's law V =IR R = V/I =230/1 =230 ohm

Description : If resistance is 8 Ohm and current is 16 ampere then what will be the voltage and power?

**Answer** : 128 volts ,2048 watts

Description : 1. What is a Dental formula of man? 2. What is the maximum permissible period between two sessions of a State Legislative Assembly? 3. What is the most abundant metal in the earth's crust? 4. ... lowest temperature of air? 20. Which Gupta ruler was related to the Licchavis on his mother's side?

**Answer** : Answer : 1. 2123/2123 2. Six months 3. Aluminium 4. Tamil Nadu 5. Pashupati 6. Canine teeth 7. Nitrogen oxide 8. Sexual reproduction 9. Rotation of Earth 10. Sravasti 11. National Development ... 15. Darius I 16. Hockey 17. Photobiology 18. Sardar Patel 19. Just before sunrise 20. Samudragupta

Description : Three friends X, Y and Z run a running race, Y finished 12 meters ahead of Z and 18 m ahead of X, while Z finished 8m ahead of X. If each friends runs the entire distance at their respective constant speeds, what is the length of the race? a) 16m b) 48m c) 24m d) 12m

**Answer** : B Let the length of the race track be 'd'. When Y finished the race, X and Z would have run (d−18) and (d−12) meters respectively. When Z finishes the race, X would have run (d-8) meters. The ratio of ... d2 -20d+96= d2 -18d 20d-18d=96 d=96/2=48m hence the length of the race track is 48m

Description : When the speed of car is doubled, then what will be the braking force of the car to stop it in the same distance ? (1) four times (2) two times (3) half (4) one-fourth

**Answer** : four times

**Answer** : Three 3 ohm resistors are connected to form a triangle. 2 ohms is the resistance between any two of the corners.

Description : Manish, Rahul and Bharti have some stones with each of the. Five times the number of stones with Rahul equals seven times the number of stones with Manish while five times the number of stones with Manish equals seven ... there with all three of them put together? A) 113 B) 109 C) 93 D) 97 E) NONE

**Answer** : Answer: B

Description : Three friends started a Company, let there names are P, Qand R. What profit Q will get, if, 1. R invested Rs. 4000 for nine months, his profit was 3/2 times that of Q's and his investment was four times that of P. 2. ... year end. A) Only 1 and 3 B) Only 1 and 2 C) All 1, 2 and 3 D) None of above

**Answer** : Answer: C) 1 and 2 will give : R = Rs. (4000 x 9) for 1 year = Rs. 36000 for 1 year. P = Rs. (1/4 * 4000 * 12 ) for 1 year = Rs 12000 for 1 year Q = Rs 24000 for one year R:P:Q = ... Profit = 500 Now from the ratio and total profit we can get Share of R. R share will be = 500 * 2/6 = 166.66

Description : The ratio of salary of two persons X and Y is 5:8. If the salary of X increases by 60% and that of Y decreases by 35% then the new ratio of their salaries become 40:27. What is X's salary? a) Rs.15000 b) Rs.12000 c) Rs.19500 d) Data inadequate. e) NONE

**Answer** : Answer : D Ratio of salary of X and Y is 5:8 Let the original salary of X and Y be Rs.5k and Rs.8k respectively. After increasing 60%, new salary of X = 160% of 5k = 160x5k/100 = 80k/ ... does not give the value of k; so that we cannot find X's exact salary. Hence the answer is data inadequate.

Description : The salary of two friends Ramu and Raju are in the ratio 4:5. If the salary of each one increases by Rs.6000, then the new ratio becomes 48:55. What is Raju's present salary? a) Rs.10500 b) Rs.10500 c) Rs.11500 d) Rs.12500

**Answer** : Answer : B Ratio their salary is 4:5 Let the original salary of Ramu and Raju be 4k and 5k respectively. After increasing Rs.6000, the ratio becomes 48:55 That is, (4k+6000)/(5k+6000) = 48/55 ... of Raju; that is, 5k. If 20k = 42000 then 5k = 10500. Hence the required answer is Rs.10500

Description : Every year before the Diwali festival, the kumaran stores increases the price of the product by 48% and then introduce two successive discount of 12% and 13% respectively. What is percentage loss and percentage gain ?

**Answer** : Let CP = 100, 48 % increase =>SP = 148 12 % discount in SP => ((148 x 12)/100) = 17.76 So 1st SP = (148 – 17.76) = 130.24 13 % discount in 1st SP ((130.24x13)/100) = 16.93 2nd SP = 130.24-16.93= 113.31 So finally CP = 100, SP = 113.31 => gain = 13.31%

Description : There were 32 boys in a hostel. If the number of boys be increased by 15, then the expenditure on food increases by Rs. 43 per day while the average of expenditure of boys is reduced by Rs. 2. What was the initial expenditure on food per day? A) Rs.108.2 B) Rs.125.6 C) Rs.135.8 D) Rs.144.5

**Answer** : Answer: A) Let initial expense of 32 boys = Rs. x average expense of 32 boys = x/32 average expense of 47 boys = (x + 43)/ 47 then, (x/32) - ((x+43)/47) = 2 x= Rs.108.28

Description : A Fuse wire is characterised by (1) High resistance and low melting point (2) High resistance and high melting point (3) Low resistance and high melting point (4) Low resistance and low melting point

**Answer** : Low resistance and low melting point

Description : Safety fuse wire used in domestic electrical appliances is made of metal of low (1) Resistance (2) Melting point (3) Specific gravity (4) Conductance

**Answer** : Melting point

Description : A bird sitting on a high tension electric wire does not get electrocuted because (1) it has high resistance (2) the body is earthed (3) it does not form a closed path for the flow of current (4) its feet are good insulators

**Answer** : it does not form a closed path for the flow of current

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