How do I use Ohm's law to show that power can be expressed by the equation P=I^2R?

1 Answer

Answer :

Are you allowed to also use the relationship that P=IV? Because given that equation, it is then just a matter of simple replacement. V=IR (Ohm’s law), so replace the V in the first equation with IR to get P=I^2R.

Related questions

Description : Electrical power is expressed in _____________. A. ohms B. volts C. amps D. watts

Last Answer : Answer: D

Description : From the L ineweaver-Burk p lot of Michaelis-Menten equation, Km and Vmax can be determined when V is the reaction velocity at substrate concentration S, the X-axis experimental data are expressed as (A) 1/V (B) V (C) 1/S (D) S

Last Answer : Answer : C

Description : If `(2p+5q)/(2r+5s) = (4p-3q)/(4r-3s)`, then find the relation between p, q, r and s.

Last Answer : If `(2p+5q)/(2r+5s) = (4p-3q)/(4r-3s)`, then find the relation between p, q, r and s.

Description : The difference of pressure between the inside and outside of a liquid drop is (A) p = T × r (B) p = T/r (C) p = T/2r (D) p = 2T/r

Last Answer : Answer: Option D

Description : On equating the generic form of current density equation and the point form of Ohm’s law, we can obtain V=IR. State True/False. a) True b) False

Last Answer : a) True

Description : The continuity equation is a combination of which of the two laws? a) Ohm’s law and Gauss law b) Ampere law and Gauss law c) Ohm’s law and Ampere law d) Maxwell law and Ampere law

Last Answer : b) Ampere law and Gauss law

Description : AC circuits develop resistance, inductance, and capacitance. The inductive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: A

Description : Alternating current circuits develop resistance, inductance, and capacitance. The capacitance of individual capacitors is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: D

Description : Alternating current circuits develop resistance, inductance and capacitance. The inductance of a coil is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: C

Description : AC circuits possess characteristics of resistance, inductance, and capacitance. The capacitive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: A

Description : Electric current may be expressed in which one of the following units? w) coulombs/volt x) joules/coulomb y) coulombs/second z) ohms/second

Last Answer : ANSWER: Y -- COULOMBS/SECOND

Description : If reading AC current with the illustrated device and unsure of the range as a precaution , the first step should be to _________. EL-0047 A. secure power and test for voltage B. disconnect the ... resistance and use Ohm's law to calculate current D. unable to safely measure current with the device

Last Answer : Answer: A

Description : The logistic population growth is expressed by the equation (a) dt / dN = Nr K N K  −      (b) dN / dt = rN K N K  −      (c) dN / dt = rN (d) dN / dt = rN N K N  −    

Last Answer : (b) dN / dt = rN K N K  −   

Description : When the Maxwell equation is expressed in frequency domain, then which substitution is possible? a) d/dt = w/j b) d/dt = j/w c) d/dt = jw

Last Answer : c) d/dt = jw

Description : The velocity of a ball tossed vertically into the air is expressed by the equation v(t) = -32t + 4, where t is given in seconds. Give the velocity of the ball when it reaches its highest point. 

Last Answer : ANSWER: 0

Description : Centroid of the are of circle shown in adjacement figure is a.r sin (?/2)/2 ?, 0 b.r sin (?)/?, 0 c.2 r sin (?/2)/?, 0 d.107 dynes e.2r sin (?)/?, 0

Last Answer : c. 2 r sin (?/2)/?, 0

Description : solve the system of equations 2r + 2s = 50 and 2r – s = 17. -General Knowledge

Last Answer : Subtract eq1 from eq2: (2r – s = 17) - (2r + 2s = 50): -3s = -33 s = -33/-3 s = 11 Solve for r: 2r + 2(11) = 50 2r = 22 = 50 2r = 50 - 22 2r = 28 r = 28/2 r = 14 set: r = 14, s = 112r + 2s = 50 and 2r – s = 17

Description : If the radius of a sphere is 2r, then its volume will be -Maths 9th

Last Answer : As, r=2r Volume of sphere = 4​/3π(2r)^3 =32/3​πr^3

Description : If the radius of a sphere is 2r, then its volume will be -Maths 9th

Last Answer : (d) Given, radius of a sphere = 2r Volume of a sphere =4/3 π(Radius)3 = 4/3 π(2r)3 = 4/3 π 8r3 = (32 πr3)/3 cu units Hence the volume of a sphere is (32 πr3)/3 cu units.

Description : Without finding the cubes, factorise: (2r-3s)3 +(3s -5t)3+ (5t-2r)3. -Maths 9th

Last Answer : Solution :-

Description : The radius of sphere is 2r, then find its volume. -Maths 9th

Last Answer : Volume of the sphere = 4/3.π.(2r)3 = 32/3πr3

Description : In the circuit diagram,heat produces in R, 2R and `1.5 R` are in the ratio of

Last Answer : In the circuit diagram,heat produces in R, 2R and `1.5 R` are in the ratio of A. `4:2:3` B. `8:4:27` C. `2:4:3` D. `27:8:4`

Description : If r is the radius of a circle and d is its diameter is an equivalent formula for the circumference C 2r?

Last Answer : Circumference of a circle: 2*pi*radius or diameter*pi

Description : If r is the radius of a circle and d is its diameter is an equivalent formula for the circumference C 2r?

Last Answer : Circumference of a circle: 2*pi*radius or diameter*pi

Description : When the following expression is written in simplest form what is the coefficient of the variable term -1.5r plus 6r and ndash 12.2r?

Last Answer : When the following expression is written in simplest form what is the coefficient of the variable term -1.5r plus 6r and ndash 12.2r?

Description : Weight of a person at a height of 2R from the centre of the earth, where R is the radius of the earth- (1) remains same (2) becomes half (3) becomes twice (4) becomes one-fourth

Last Answer : (4) becomes one-fourth Explanation: The gravitational force is proportional to 1/R2, where R is the distance from the centre of the Earth. So at a height of 2R from the centre of the earth, the corresponding weight would be one-fourth of the original weight.

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 - (1) R/4 (2) R/2 (3) R (4) 2R

Last Answer : (1) R/4

Description : A centrifugal filtration unit operating at a rotational speed of w has inner surface of the liquid (density ρL) located at a radial distance R from the axis of rotation. The thickness of the liquid film is δ and no cake is formed. The ... . ρL (C) ½w 2 . δρL (2R + δ) (D) ½w 2 . R . ρL(R + 2δ)

Last Answer : (C) ½w 2 . δρL (2R + δ)

Description : Velocity of escape is equal to A. r √(2g); where r: radius of Earth or any other planet for that matter, g: gravitational field strength B. g √(2r); where r: radius of ... (2gr); where r: radius of Earth or any other planet for that matter, g: gravitational field strength

Last Answer : √(2gr); where r: radius of Earth or any other planet for that matter, g: gravitational field strength

Description : Heat produced when a steady state current, I passes through an electrical conductor having resistance, 'R' is (A) IR (B) I 2R (C) IR 2 (D) I 2R

Last Answer : (B) I 2R

Description : What are the advantages and disadvantages of R-2R ladder DAC?

Last Answer : Advantage: • Easier to build • Number of bits can be expanded by adding more sections. Disadvantage: • More power dissipation makes heating, which in turns develops non-linearties in DAC.

Description : The radius of Gyration (k) for Rim Type Flywheel having radius ‘r’ is given by 1. k = 2r 2. k = r/2 3. k = r 4. k = r/3

Last Answer : 3. k = r

Description : . In case of turbulent flow of fluid through a circular pipe, the (A) Mean flow velocity is about 0.5 times the maximum velocity (B) Velocity profile becomes flatter and flatter with ... , shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

Last Answer : (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

Description : The following gas phase reactions are carried out isothermally in a CSTR. A → 2R ; r1 = k1pA ; k1 = 20mole/(sec.m3 bar) A → 3S ; r2 = k2 pA ; k2 = 40mole/(sec.m3 .bar) What is the maximum possible value of FR(mole/sec.)? (A) 1/3 (B) 1/2 (C) 2/3 (D) 2

Last Answer : (C) 2/3

Description : The approximate formula for radial or perpendicular offsets from the tangent, is (A) x/2R (B) x²/2R (C) x/R (D) x²/R

Last Answer : (B) x²/2R

Description : The degree of kinematic indeterminacy of a pin-jointed space frame is (A) 2j - r (B) 3j - r (C) j - 2r (D) j - 3r Where j is number of joints and r is reaction components

Last Answer : (B) 3j - r

Description : Degree of kinematic indeterminacy of a pin-jointed plane frame is given by (A) 2j - r (B) j - 2r (C) 3j - r (D) 2j + r

Last Answer : (A) 2j - r

Description : The centre of percussion of a solid cylinder of radius r resting on a horizontal plane will be  (A) r/2  (B) 2r/3  (C) r/A (D) 3r/2 

Last Answer : (D) 3r/2 

Description : If T and R are tread and rise respectively of a stair, then (A) 2R + T = 60 (B) R + 2T = 60 (C) 2R + T = 30 (D) R + 2T = 30

Last Answer : Answer: Option A

Description : If L is the length of a moving vehicle and R is the radius of curve, the extra mechanical width b to be provided on horizontal curves, (A) L/R (B) L/2R (C) L²/2R (D) L/3R

Last Answer : Answer: Option C

Description : The total energy of electron in the Bohr orbit is given by the formula, E = a) - ke2 /2r b) - ke2 /2r2 c) - k 2 e/2r d) - ke2 /r

Last Answer : a) - ke2 /2r

Description : 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

Description : Three resistors of resistance R are connected in various ways, which of the following cannot be obtained? a. 3R ohm b. 2R/4 ohm c. R/3 ohm d. 2R/3 ohm

Last Answer : b. 2R/4 ohm

Description : Electrical energy is converted to heat at the rate of a. IRt b. I 2R c. I 2Rt d. VIt

Last Answer : b. I 2R

Description : In a binary Hamming code the number of check digits is r then number of message digits is equal to: (A) 2r-1 (B) 2r-r-1 (C) 2r-r+1 (D) 2r+r-1

Last Answer : (B) 2r-r-1

Description : Below are the few steps given for scan-converting a circle using Bresenham's Algorithm. Which of the given steps is not correct? (1) Compute d = 3 – 2r (where r is radius) (2) Stop if x> y (3) If d

Last Answer : If d≥0,then d=4 *(x-y)+10, x=x+1 and y=y+1

Description : In an R-2R ladder D/A converter, the input resistance is  1. Not same for all digital inputs 2. R for each input 3. 2R for each input 4. 3R for each input 

Last Answer : In an R-2R ladder D/A converter, the input resistance is 3R for each input 

Description : A 4-bit R/2R digital-to-analog (DAC) converter has a reference of 5 volts. What is the analog output for the input code 1010:  (1) 0.3125 V (2) 3.125 V (3) 0.78125 V (4) –3.125 V

Last Answer : 3.125V

Description : General crushing equation is given by d(P/m) = -K (dD̅S /D̅ n S ). Bond's crushing law is obtained by solving this equation for n = __________ and feed of infinite size. (A) 1 (B) 1.5 (C) 2 (D) 2.5

Last Answer : (B) 1.5

Description : Which of the following is the Ideal gas law (equation)?  A. V/T = K  B. V= k*(1/P)  C. P1/T1 = P2/T2  D. PV = nRT

Last Answer : PV = nRT