Saved Bookmarks
This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The electric field produce due to time varying electric field..? |
|
Answer» Explanation:According to Faraday's LAW, changing magnetic field causes electric field. you can see this more clearly when WORKING with the differential form of Maxwell's equations. ... So time VARYING electric fields act LIKE currents and can CREATE magnetic fields, i.e. act as sources for magnetic fields just as current densities do |
|
| 2. |
(d) absence of inertia 2. An object of mass m held against avertical wall by applying horizontalforce F as shown in the figure. Theminimum value of the force Fis(IIT JEE 1994)WallFm(a) Less than mg(b) Equal to mg(c) Greater than mg(d) Cannot determine3. A vehicle is moving along the positx direction, if sudden brake is applied,then(a) frictional force acting on thevehicle is along negative xdirection(b) frictional force acting on thevehicle is along positive x direction(c) no frictional force acts on thevehicle(d) frictional force acts in downwarddirection. Please reply answer |
| Answer» 1 :-B2:-C3 :- B is the ANSWER | |
| 3. |
An electron perform circular motion of radious r, perpendicular to uniform magnetic field B. The kinetic energy gained by this electron in half revolution is _______ . (A) 1/2 mv² (B) 1/4 mv² (C) zero (D) πrBev |
|
Answer» c zeroExplanation:the electron will move in circular MOTION with CONSTANT VELOCITY THUS change in velocity is zero and so is the kinetic ENERGY |
|
| 4. |
A particle of mass m has an electric charge q. This particle is accelerated through a potential difference V and then entered normally in a uniform magnetic field B. It performs a circular motion of radius R. The ratio of its charge to the mass (q/m) is = ______ [(q/m) is also called specific charge.] (A) 2V/B²R² (B) V/2BR (C) VB/2R (D) mV/BR |
| Answer» IO of its charge to the mass (q/m) is Given:Mass of the particle = mCharge of the particle = qVelocity of the particle = vPotential DIFFERENCE = VMagnetic field = BRadius of the motion = R To find:Ratio of charge to the mass = ?Solution:From question, the particle is electron which is accelerated through potential difference.By energy conversion:SINCE, the particle ENTERS MAGNETIC field, magnetic field is:The velocity of the electron is given by the formula:On squaring on both sides, | |
| 5. |
Two wires which are made of the same material have the same cross-sectional area, but different lengths l₁ and l₂. Prove that if they are used as fuse wires, they will melt for the same value of the current flowing through them, in the same time. |
|
Answer» their AREAS are differentExplanation: P(RHO) = R A/lp1= p2A1/l1 = A2/l2A1/A2 = l1/l2 |
|
| 6. |
An electric kettle has two heating coils. When one of the coils is switched on, a given quantity of water in the kettle starts boiling in 6 minutes. When the other coil only is switched on, then the same amount of water starts boiling in 8 minutes. If the two coils are switched on in the same amount of water starts boiling in 8 minutes. If the two coils are switched on in parallel how much time will the same amount of water take to boil ? Each time the voltage applied is the same. |
|
Answer» the ANSWER is to be 8minute |
|
| 7. |
what is electric motor and what principle does it work what is the function of the split ring in an electric motor name three device work with a motor |
|
Answer» Explanation:LEFT HAND rule It work Its provide mechanical work |
|
| 8. |
19. Two point charges of 2C and - 6C attract each other with a force of 12N. A negative charge of 2C is added to -6c charge. Now the force between them is1) 12 N2) 16 N3) 32 N4) 24 N |
| Answer» TION:your ANSWER is,24N.hope it will HELP you | |
| 9. |
What are derived Quantities ?? |
| Answer» QUANTITIES which have a proper VALUE..... And proper definition are SAID to be DERIVED quanties | |
| 10. |
two vessels having base area in the ratio 1 is to 2 are filled with water to the same height is the amount of water in them are in the ratio 1 is to 4 then the ratio of pressure on their bottoms will be |
|
Answer» kjgdghkglfbgExplanation:buvlfhhjghfhghfjhg |
|
| 12. |
Passengers are pushed towards the right due to inertia of direction why ❓ what the reason? Please reply fast |
| Answer» ERS are pushed toward the right due to inertia of DIRECTION because the inertia of direction is CONSTANT on legs so,when it feels inertia then it CHANGES its direction according to it but the REST part doesn't have same inertia which is the reason they are not in that inertia. | |
| 13. |
Show that a pure inductive ac circuit consumes no power. |
| Answer» POWER =0 EXPLANATION:in Photos i just enhance the DERIVATION. That is note so pong | |
| 15. |
Please answer this Class 11 CBSE physics... I will mark braniest for correct answer |
|
Answer» ............................ |
|
| 16. |
Two point charges 2C and -6C attract each other with a force of 12N.A negative charge of 2C is added to -6C charge.Now the force between them is a.12N b.16N c.32N d.24N |
|
Answer» yes here is your answerExplanation:2C,-6C is multiplied then the answer is -12N you GAVE the option is 12c and after 2c is having + sign -6c is having SUBTRACTION sign then you should MULTIPLY both the signs '-' muntiplied with +'= +so it is 12c |
|
| 17. |
What are the fundamental QUANTITIES ?? |
|
Answer» tesHere is your ANSWER FUNDAMENTAL QUANTITIES : The PHYSICAL quantities which can be treated as independent of other physical quantities and are not usually defined in terms of other physical Quantities are CALLED fundamental quantities....hope it helps uh #cutedoll07 |
|
| 18. |
One conducting wire of length 1 m is cut into two unequal part P and Q respectively. Now, part P is stretched to double its length. Let the modified wire be R. If the resistance of the R and Q wires are same, then calculate the length of P and Q wires. |
|
Answer» udent,◆ Answer -p = 20 cmq = 80 CM● Explanation -# Given -l = 1 m = 100 cm# Solution -Let p and q represents lengths of two segments.When P is stretched to double its length, its cross-sectional area will be halved. Resistance of stretched WIRE P is -Rp = ρ.(2P)/(A/2)Rp = 4ρp/ALength of wire Q will be q = 100-p. So now resistance of wire Q is -Rq = ρ.(100-p)/AGiven that,Rp = Rq4ρp/A = ρ.(100-p)/A4p = 100-p5p = 100p = 20 cmNow,q = 100-pq = 100-20q = 80 cmThus, length of P and Q is 20 cm and 80 cm respectively.Thanks dear... |
|
| 19. |
A stream of electron moves from the electron gun to a screen of a television. The electric current of the 10 μ A is constituted. Calculate the number of electrons striking the screen at every second. Also calculate magnitude of the charges striking the screen in one minute. |
| Answer» | |
| 20. |
An electron in the hydrogen atom is revolving around a proton with a speed of e²/h. The radius of the electron orbit is equal to ♄²/me². Obtain the formula for the electric current in the above case. Mass of the electron = m, charge on electron = e. |
|
Answer» udent,◆ ANSWER -I = me⁵/2πh³◆ Explanation -Let t be TIME TAKEN by electron to complete a revolution.t = circumference/speedt = 2πr/vt = 2π × (h²/me²) / (e²/h)t = 2πh³/me⁴Electric current is given by -I = charge/timeI = E/tI = e/(2πh³/me⁴)I = me⁵/2πh³Therefore, electric current produced in atom is me⁵/2πh³.Thanks dear... |
|
| 21. |
A current of 1.0 A is flowing through a copper wire of length 0.1 m and corss-section 1.0 X 10⁻⁶ m². (i) If the resistivity of copper be 1.7 x 10⁻⁸ Ω m, calculate the potential difference across the ends of a wire. (ii) Determine the drift velocity of electrons. [Density of copper = 8.9 x 10³ kg m⁻³, valancy of Cu = 1, atomic weight of copper = 63.5 g mol⁻¹, NA = 6.02 x 10²³ mo1⁻¹] |
|
Answer» udent,◆ Answer -(i) Potential difference = 1.7×10^-3 V(ii) DRIFT velocity = 7.4×10^-5 m/s◆ Explaination -(i) Potential difference ACROSS wire is -V = IRV = Iρl/AV = 1 × 1.7×10^-8 × 0.1 / 10^-6V = 1.7×10^-3 V(ii) No of electrons per cu.m. is -n = valence × NA × d / MN = 1 × 6.022×10^23 × 8.9×10^3 / 63.5×10^-3n = 8.44×10^28 /m^3Drift velocity of electrons is GIVEN by -v = I/(nAe)v = 1 / (8.44×10^28 × 10^-6 × 1.6×10^-19)v = 7.4×10^-5 m/sHope this HELPS you... |
|
| 22. |
What is Joule heat and Joule effect ? Obtain Joule's law for Joule heating. |
|
Answer» tion:Joule effect. ... "Joule's FIRST law" (Joule heating), a physical law expressing the relationship between the heat generated and current flowing through a conductor. Joule's SECOND law STATES that the internal energy of an ideal gas is independent of its volume and PRESSURE, depending only on its temperature. |
|
| 23. |
Obtain the relation between the drift velocity and current density. |
|
Answer» tion:AVARAGE velocity of free flowing ELECTRON of OBTAIN electron applying potantial differens is known as DRIFT velocity. |
|
| 24. |
DIMENSIONALLY ANALYZE V^{2}=U^{2}+2AS |
|
Answer» V= FINAL VELOCITY = [LT-¹]u= initial velocity=[LT-¹]a= ACCELERATION =[LT-²]s= distance= [L]v²=u²+ 2AS=>v²-u²=2as[LT-¹]²-[LT-¹]²=2[LT-²][L][L²T-²][L²T-²]=2[L²T-²]2[L²T-²]=2[L²T-²]2 is dimensionlesshence provedRead more on Brainly.in - brainly.in/question/1669063#readmore |
|
| 25. |
State fliming right Hand Rule |
|
Answer» Fleming's Right-hand RULE (for generators) SHOWS the direction of induced current when a conductor attached to a circuit moves in a magnetic field. It can be USED to DETERMINE the direction of current in a generator's windings.hope it helps u mate |
|
| 26. |
What is the relationship between e.m.f and terminal voltage? |
| Answer» REFER to the ATTACHMENT... | |
| 27. |
Haven't anyone found the causes of motion |
|
Answer» When a force acts (pushes or pulls) on an object, it CHANGES the object's speed or direction (in other WORDS, makes it ACCELERATE). The bigger the force, the more the object accelerates. When a force acts on an object, there's an EQUAL force (called a reaction) acting in the OPPOSITE direction. |
|
| 28. |
What are physical quantities ?? |
|
Answer» tesHere is your answer Physical quantities : All those quantities which can be measured DIRECTLY or indirectly and in TERMS of which the laws of physics can be EXPRESSED are called PHYSICAL QUANTITIES....HOPE it helps uh #cutedoll07 |
|
| 29. |
Plz explain this Ray diagram |
|
Answer» an object PQ is placed in front of any erecting prism .the first Ray strike the surface of the prism AB and passes in a SLANTING position and reaches and strikes the surface AC . another ARRAY from the lower surface of the object that is kyon passes the prism and strikes the base of the prism and then passes in as landing position then strikes a surface of the prism that is bcdon't forget to draw the normal and it will make an angle of 45 DEGREE as the prism is 90 45 45 prism.the two days leave the pressure by striking the surface BC and they join to form the image that is Q'P'. |
|
| 30. |
19. A body moving along straight line covers a distance in three equal parts with speed 2 m/s, 3 m/s and4 m/s, then its average speed is(1) 12 m/s(2) 13/12 m/s(3)36/13 m/s(4)12/13 m/s |
|
Answer» 36/13m/sif it is CORRECT PLS FOLLOW LIKE and mark as brainliest |
|
| 31. |
uniform electric and magnetic field are produced pointing in the same direction an electron is projected in the direction of the field what will be the effect on the kinetic energy of the electron due to the two fields? |
|
Answer» When E, V and B are all ALONG same direction, then , magnetic force experienced by electron is zerowhile ELECTRIC force is ACTING OPPOSITE to velocity of electron, so velocity of electron will decrease. |
|
| 32. |
9. State which of the following situations are possible and give an example for each of these:(a) an object with a constant acceleration but with zero velocity(b) an object moving with an acceleration but with uniformspeed.(c) an object moving in a certain direction with anacceleration in the perpendicular direction. |
|
Answer» C) EXPLANATION:Because acceleration due to gravity will act in perpendicular direction while object is moving forward.Also A) is not possible as acceleration INVOLVES change in VELOCITY but change in velocity will not take place if velocity is zero.Also B) is not possible as change in velocity will not take place if velocity is CONSTANT |
|
| 33. |
Q.5 Newton's second law can give a measure of: (a) Force (b) Acceleration(c) Rate of change of momentum (d) All of above |
| Answer» SWER is-HOPE IT HELPS UH | |
| 34. |
if energy (E) , velocity(v) and force (F) be taken as fundamental quantity then what are the dimension of mass |
|
Answer» [M^0 L^0 T^0]. M will DIMENSION LESS. EXPLANATION:because if we do E÷V×F. Then we GET M is a dimension less QUANTITY. |
|
| 35. |
A body released from the top of a tower falls through a height of 5m during the first second of its fall and35m during the last second of its fall. The height ofthe tower is(A) 80 m(B) 60 m(C) 40m(D) 20 m |
| Answer» | |
| 36. |
Explain the mobility of a charge carrier and obtain the formula for the conductivity of a semiconductor. |
| Answer» TION:HOPE this HELPS you CHILD | |
| 37. |
Explain the emf of a battery. When the battery is said to be in "open circuit condition" ? |
|
Answer» tion:When the battery is said to be open circuit or no current flow in circuit then emf of CELL is equal to terminal VOLTAGE And while emf is greater when cell in USE Thank you |
|
| 38. |
Write Ohm's law. Explain the 1—V characteristics for a conductor obeying Ohm's law. |
|
Answer» nstant temperature the potential difference between TWO ends of a conductor through which ELECTRIC current is passing is DIRECTLY proportional to the current flowing through it. V = IR When resistance and current is 1 unit then the potential difference is 1V. V = 1 A × 1 OhmV = 1V . |
|
| 39. |
Give the empirical formula showing the relation between the resistivity of a metallic conductor and temperature. |
|
Answer» tion:When the temperature is increased, the atoms of the MATERIAL VIBRATE and it makes the VALENCE electrons present in the valence band to SHIFT to the conduction band. ... When the conductivity of the material INCREASES, it means that the resistivity decreases and so the current flow increases |
|
| 40. |
Why the current in a superconductor can be sustained over a long interval of time ? |
|
Answer» a superconductor could EASILY release its electron and has a greater tendency to conduct electricity and hence very LESS energy is CONSUMED in overcoming the RESISTANCE of superconductor ends the electricity could be SUSTAINED in a superconductor for long interval of time |
|
| 41. |
Two bulbs of 220 V and 100 W are first connected in series and then in parallel with a supply of 220 V. Total power in both the cases will be ______ .(A) 50 W, 100 W (B) 100 W, 50 W(C) 200 W, 150 W (D) 50 W, 200 W |
|
Answer» n Series = P1 + P2 => 100 + 100=> 200 WPower in Parallel = 1/p1 + 1/p2=> 1/P = 1/100 + /100=> 1/P = 2/100=> 1/P = 1/50=> P = 50WTherefore, D is correct |
|
| 42. |
If the current in an electric bulb increases by 1 %, what will be the change in the power of a bulb ?[Assume that the resistance of the filament of a bulb remains constant.](A) increases by 1 % (B) decreases by 1 %(C) increases by 2 % (D) decreases by 2 % |
|
Answer» Option (C): The power will increase by 2%.Explanation:Assumptions:I = Current through the bulb.V = POTENTIAL difference across the bulb.R = resistance of the bulb.We know,Power of bulb is given by.Using OHM's law,.Therefore, .Now, the current is increased by 1%.LET the new current by , such that,.And the resistance is same.Therefore, the new power will BETHE % change in power is given by Since, , therefore the power has increased.Thus, the correct option is (C). |
|
| 43. |
A wire is uniformly stretched to make its area of cross-section 1/nᵗʰ times (n > 0). What will be its new resistance (A) 1/n² times (B) n² times (C) 1/n times (D) n times |
|
Answer» udent,◆ Answer -(B) n² TIMES ● Explanation -Before STRETCHING, specific resistance of wire is -ρ = RA/lEven after stretching, volume of STRETCHED wire will remain same.V = V'l.A = l'.A'l.A = l'.A/nl' = l.nResistance of new wire will be -R' = ρ.l'/A'R' = (RA/l) × (l.n) / (A/n)R' = R.n²Therefore, new resistance of the wire will n² times of old one.Hope that's all... |
|
| 44. |
This is the question.....I need quick answer |
|
Answer» the answer will be 40 CM Explanation:GIVE me THANKS and FOLLOW me I will follow you |
|
| 45. |
Two liquids of densities d1, d2 are mixed with masses in the ratio 3:5. Find the density of mixture |
| Answer» L have FOUND the PERCENTAGE of DENSITY in the PHOTO | |
| 46. |
What is the pattern of magnetic field lines around a straight current carrying conductor sketch it |
|
Answer» A CURRENT CARRYING conductor creates a magnetic field around it, which can be COMPREHENDED by using magnetic lines of FORCE or magnetic field lines. The nature of the magnetic field lines around a straight current carrying conductor is concentric circles with centre at the axis of the conductor. |
|
| 47. |
Q.4 Inertia of a body is that property, by virtue of which the body is unable to change by itself, its:(a) State of rest(b) State of uniform motion(c) Direction of motion(d) All the above |
| Answer» | |
| 48. |
What is the movement of air from warmer to colder and from colder to warmer regions called please answeri need help |
| Answer» LAND BREEZE and SEA breeze | |
| 49. |
Q.3 Two bodies are dropped from two different heights h1 and h2. one of them is dropped directly down, while the other is projected with a horizontalvelocity of 10m/s. it is found that both reach the ground with same speed (g= 10 m/s2). Then:(a) hı=h2(c) h1-h2 = 5m(b) h1/h2 = √10(d) given condition is impossible to achieve. |
| Answer» OPTION a.they are DIRECT formula.you can USE it | |