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Question Number 16504    Answers: 2   Comments: 0

An object moves in a circular path with a constant speed in the xy plane with the centre at the origin. When the object is at x = −2 m, its velocity is −(4 m/s)j^∧ . Then objects velocity at y = 2 m is (1) 4 m/s i^∧ (2) (−4 m/s) i^∧ Using this data, find objects acceleration when it is at y = 2 m (1) 8 m/s^2 i^∧ (2) −8 m/s^2 j^∧

$$\mathrm{An}\:\mathrm{object}\:\mathrm{moves}\:\mathrm{in}\:\mathrm{a}\:\mathrm{circular}\:\mathrm{path}\:\mathrm{with} \\ $$$$\mathrm{a}\:\mathrm{constant}\:\mathrm{speed}\:\mathrm{in}\:\mathrm{the}\:\mathrm{xy}\:\mathrm{plane}\:\mathrm{with} \\ $$$$\mathrm{the}\:\mathrm{centre}\:\mathrm{at}\:\mathrm{the}\:\mathrm{origin}.\:\mathrm{When}\:\mathrm{the} \\ $$$$\mathrm{object}\:\mathrm{is}\:\mathrm{at}\:{x}\:=\:−\mathrm{2}\:\mathrm{m},\:\mathrm{its}\:\mathrm{velocity}\:\mathrm{is} \\ $$$$−\left(\mathrm{4}\:\mathrm{m}/\mathrm{s}\right)\overset{\wedge} {{j}}.\:\mathrm{Then}\:\mathrm{objects}\:\mathrm{velocity}\:\mathrm{at} \\ $$$${y}\:=\:\mathrm{2}\:\mathrm{m}\:\mathrm{is} \\ $$$$\left(\mathrm{1}\right)\:\mathrm{4}\:\mathrm{m}/\mathrm{s}\:\overset{\wedge} {{i}} \\ $$$$\left(\mathrm{2}\right)\:\left(−\mathrm{4}\:\mathrm{m}/\mathrm{s}\right)\:\overset{\wedge} {{i}} \\ $$$$\mathrm{Using}\:\mathrm{this}\:\mathrm{data},\:\mathrm{find}\:\mathrm{objects}\:\mathrm{acceleration} \\ $$$$\mathrm{when}\:\mathrm{it}\:\mathrm{is}\:\mathrm{at}\:{y}\:=\:\mathrm{2}\:\mathrm{m} \\ $$$$\left(\mathrm{1}\right)\:\mathrm{8}\:\mathrm{m}/\mathrm{s}^{\mathrm{2}} \:\overset{\wedge} {{i}} \\ $$$$\left(\mathrm{2}\right)\:−\mathrm{8}\:\mathrm{m}/\mathrm{s}^{\mathrm{2}} \:\overset{\wedge} {{j}} \\ $$

Question Number 16499    Answers: 1   Comments: 0

A particle is moving in parabolic path x^2 = y, with constant speed u. Find the acceleration of the particle when it crossess origin. Also find the radius of curvature at origin.

$$\mathrm{A}\:\mathrm{particle}\:\mathrm{is}\:\mathrm{moving}\:\mathrm{in}\:\mathrm{parabolic}\:\mathrm{path} \\ $$$${x}^{\mathrm{2}} \:=\:{y},\:\mathrm{with}\:\mathrm{constant}\:\mathrm{speed}\:{u}.\:\mathrm{Find}\:\mathrm{the} \\ $$$$\mathrm{acceleration}\:\mathrm{of}\:\mathrm{the}\:\mathrm{particle}\:\mathrm{when}\:\mathrm{it} \\ $$$$\mathrm{crossess}\:\mathrm{origin}.\:\mathrm{Also}\:\mathrm{find}\:\mathrm{the}\:\mathrm{radius}\:\mathrm{of} \\ $$$$\mathrm{curvature}\:\mathrm{at}\:\mathrm{origin}. \\ $$

Question Number 16491    Answers: 0   Comments: 0

Men are running in a line along a road with velocity 9 km/hr behind one another at equal distances of 20 m. Cyclists are also riding along the same line in the same direction at 18 km/hr at equal intervals of 30 m. The speed with which an observer must travel along the road in opposite direction of so that whenever he meets a runner he also meets a cyclist is (1) 9 km/h (2) 12 km/h (3) 18 km/h (4) 6 km/h

$$\mathrm{Men}\:\mathrm{are}\:\mathrm{running}\:\mathrm{in}\:\mathrm{a}\:\mathrm{line}\:\mathrm{along}\:\mathrm{a}\:\mathrm{road} \\ $$$$\mathrm{with}\:\mathrm{velocity}\:\mathrm{9}\:\mathrm{km}/\mathrm{hr}\:\mathrm{behind}\:\mathrm{one} \\ $$$$\mathrm{another}\:\mathrm{at}\:\mathrm{equal}\:\mathrm{distances}\:\mathrm{of}\:\mathrm{20}\:\mathrm{m}. \\ $$$$\mathrm{Cyclists}\:\mathrm{are}\:\mathrm{also}\:\mathrm{riding}\:\mathrm{along}\:\mathrm{the}\:\mathrm{same} \\ $$$$\mathrm{line}\:\mathrm{in}\:\mathrm{the}\:\mathrm{same}\:\mathrm{direction}\:\mathrm{at}\:\mathrm{18}\:\mathrm{km}/\mathrm{hr} \\ $$$$\mathrm{at}\:\mathrm{equal}\:\mathrm{intervals}\:\mathrm{of}\:\mathrm{30}\:\mathrm{m}.\:\mathrm{The}\:\mathrm{speed} \\ $$$$\mathrm{with}\:\mathrm{which}\:\mathrm{an}\:\mathrm{observer}\:\mathrm{must}\:\mathrm{travel} \\ $$$$\mathrm{along}\:\mathrm{the}\:\mathrm{road}\:\mathrm{in}\:\mathrm{opposite}\:\mathrm{direction}\:\mathrm{of} \\ $$$$\mathrm{so}\:\mathrm{that}\:\mathrm{whenever}\:\mathrm{he}\:\mathrm{meets}\:\mathrm{a}\:\mathrm{runner}\:\mathrm{he} \\ $$$$\mathrm{also}\:\mathrm{meets}\:\mathrm{a}\:\mathrm{cyclist}\:\mathrm{is} \\ $$$$\left(\mathrm{1}\right)\:\mathrm{9}\:\mathrm{km}/\mathrm{h} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{12}\:\mathrm{km}/\mathrm{h} \\ $$$$\left(\mathrm{3}\right)\:\mathrm{18}\:\mathrm{km}/\mathrm{h} \\ $$$$\left(\mathrm{4}\right)\:\mathrm{6}\:\mathrm{km}/\mathrm{h} \\ $$

Question Number 16497    Answers: 1   Comments: 0

Two particles are revolving on two coplanar circles with constant angular velocities ω_1 and ω_2 respectively. Their time periods are T_1 and T_2 then prove that the time taken by second particle to complete one revolution more than the first particle, T, is given by T = ((T_1 T_2 )/(T_1 − T_2 ))

$$\mathrm{Two}\:\mathrm{particles}\:\mathrm{are}\:\mathrm{revolving}\:\mathrm{on}\:\mathrm{two} \\ $$$$\mathrm{coplanar}\:\mathrm{circles}\:\mathrm{with}\:\mathrm{constant}\:\mathrm{angular} \\ $$$$\mathrm{velocities}\:\omega_{\mathrm{1}} \:\mathrm{and}\:\omega_{\mathrm{2}} \:\mathrm{respectively}.\:\mathrm{Their} \\ $$$$\mathrm{time}\:\mathrm{periods}\:\mathrm{are}\:{T}_{\mathrm{1}} \:\mathrm{and}\:{T}_{\mathrm{2}} \:\mathrm{then}\:\mathrm{prove} \\ $$$$\mathrm{that}\:\mathrm{the}\:\mathrm{time}\:\mathrm{taken}\:\mathrm{by}\:\mathrm{second}\:\mathrm{particle} \\ $$$$\mathrm{to}\:\mathrm{complete}\:\mathrm{one}\:\mathrm{revolution}\:\mathrm{more}\:\mathrm{than} \\ $$$$\mathrm{the}\:\mathrm{first}\:\mathrm{particle},\:{T},\:\mathrm{is}\:\mathrm{given}\:\mathrm{by} \\ $$$${T}\:=\:\frac{{T}_{\mathrm{1}} {T}_{\mathrm{2}} }{{T}_{\mathrm{1}} \:−\:{T}_{\mathrm{2}} } \\ $$

Question Number 16466    Answers: 1   Comments: 0

Question Number 16455    Answers: 2   Comments: 0

The speed of a projectile when it is at its greatest height is (√(2/5)) times its speed at half the maximum height. What is its angle of projection?

$$\mathrm{The}\:\mathrm{speed}\:\mathrm{of}\:\mathrm{a}\:\mathrm{projectile}\:\mathrm{when}\:\mathrm{it}\:\mathrm{is}\:\mathrm{at} \\ $$$$\mathrm{its}\:\mathrm{greatest}\:\mathrm{height}\:\mathrm{is}\:\sqrt{\frac{\mathrm{2}}{\mathrm{5}}}\:\mathrm{times}\:\mathrm{its} \\ $$$$\mathrm{speed}\:\mathrm{at}\:\mathrm{half}\:\mathrm{the}\:\mathrm{maximum}\:\mathrm{height}. \\ $$$$\mathrm{What}\:\mathrm{is}\:\mathrm{its}\:\mathrm{angle}\:\mathrm{of}\:\mathrm{projection}? \\ $$

Question Number 16310    Answers: 1   Comments: 3

Question Number 16281    Answers: 0   Comments: 0

A plane moves in windy weather due east while the pilot points the plane somewhat south of east. The wind is blowing at 50 km/hr directed 30° east of north, while the plane moves at 200 km/hr relative to the wind. What is the velocity of the plane relative to the ground and what is the direction in which the pilot points the plane?

$$\mathrm{A}\:\mathrm{plane}\:\mathrm{moves}\:\mathrm{in}\:\mathrm{windy}\:\mathrm{weather}\:\mathrm{due} \\ $$$$\mathrm{east}\:\mathrm{while}\:\mathrm{the}\:\mathrm{pilot}\:\mathrm{points}\:\mathrm{the}\:\mathrm{plane} \\ $$$$\mathrm{somewhat}\:\mathrm{south}\:\mathrm{of}\:\mathrm{east}.\:\mathrm{The}\:\mathrm{wind}\:\mathrm{is} \\ $$$$\mathrm{blowing}\:\mathrm{at}\:\mathrm{50}\:\mathrm{km}/\mathrm{hr}\:\mathrm{directed}\:\mathrm{30}°\:\mathrm{east} \\ $$$$\mathrm{of}\:\mathrm{north},\:\mathrm{while}\:\mathrm{the}\:\mathrm{plane}\:\mathrm{moves}\:\mathrm{at}\:\mathrm{200} \\ $$$$\mathrm{km}/\mathrm{hr}\:\mathrm{relative}\:\mathrm{to}\:\mathrm{the}\:\mathrm{wind}.\:\mathrm{What}\:\mathrm{is} \\ $$$$\mathrm{the}\:\mathrm{velocity}\:\mathrm{of}\:\mathrm{the}\:\mathrm{plane}\:\mathrm{relative}\:\mathrm{to}\:\mathrm{the} \\ $$$$\mathrm{ground}\:\mathrm{and}\:\mathrm{what}\:\mathrm{is}\:\mathrm{the}\:\mathrm{direction}\:\mathrm{in} \\ $$$$\mathrm{which}\:\mathrm{the}\:\mathrm{pilot}\:\mathrm{points}\:\mathrm{the}\:\mathrm{plane}? \\ $$

Question Number 16271    Answers: 1   Comments: 0

The unemployment rate among workers under 25 in a state went from 8.2% to 7.5% in one year. Assume an average of 1340200 workers and estimate the decrease in the number unemployed.

$${The}\:{unemployment}\:{rate}\:{among}\:{workers} \\ $$$${under}\:\mathrm{25}\:{in}\:{a}\:{state}\:{went}\:{from}\:\mathrm{8}.\mathrm{2\%} \\ $$$${to}\:\mathrm{7}.\mathrm{5\%}\:{in}\:{one}\:{year}.\:{Assume}\:{an}\:{average} \\ $$$${of}\:\mathrm{1340200}\:{workers}\:{and}\:{estimate} \\ $$$${the}\:{decrease}\:{in}\:{the}\:{number}\:{unemployed}. \\ $$

Question Number 16616    Answers: 1   Comments: 1

A particle starts from the origin with velocity (√(44)) ms^(−1) on a straight horizontal road. Its acceleration varies with displacement as shown. The velocity of the particle as it passes through the position x = 0.2 km is [Answer: 18 ms^(−1) ]

$$\mathrm{A}\:\mathrm{particle}\:\mathrm{starts}\:\mathrm{from}\:\mathrm{the}\:\mathrm{origin}\:\mathrm{with} \\ $$$$\mathrm{velocity}\:\sqrt{\mathrm{44}}\:\mathrm{ms}^{−\mathrm{1}} \:\mathrm{on}\:\mathrm{a}\:\mathrm{straight} \\ $$$$\mathrm{horizontal}\:\mathrm{road}.\:\mathrm{Its}\:\mathrm{acceleration}\:\mathrm{varies} \\ $$$$\mathrm{with}\:\mathrm{displacement}\:\mathrm{as}\:\mathrm{shown}.\:\mathrm{The} \\ $$$$\mathrm{velocity}\:\mathrm{of}\:\mathrm{the}\:\mathrm{particle}\:\mathrm{as}\:\mathrm{it}\:\mathrm{passes} \\ $$$$\mathrm{through}\:\mathrm{the}\:\mathrm{position}\:{x}\:=\:\mathrm{0}.\mathrm{2}\:\mathrm{km}\:\mathrm{is} \\ $$$$\left[\mathrm{Answer}:\:\mathrm{18}\:\mathrm{ms}^{−\mathrm{1}} \right] \\ $$

Question Number 16156    Answers: 0   Comments: 2

A body in a uniform horizontal circular motion possesses a variable velocity. Does it mean that the K.E. of the body is also variable?

$$\mathrm{A}\:\mathrm{body}\:\mathrm{in}\:\mathrm{a}\:\mathrm{uniform}\:\mathrm{horizontal} \\ $$$$\mathrm{circular}\:\mathrm{motion}\:\mathrm{possesses}\:\mathrm{a}\:\mathrm{variable} \\ $$$$\mathrm{velocity}.\:\mathrm{Does}\:\mathrm{it}\:\mathrm{mean}\:\mathrm{that}\:\mathrm{the}\:\mathrm{K}.\mathrm{E}. \\ $$$$\mathrm{of}\:\mathrm{the}\:\mathrm{body}\:\mathrm{is}\:\mathrm{also}\:\mathrm{variable}? \\ $$

Question Number 16155    Answers: 1   Comments: 0

A body of mass m is projected with a speed v making an angle θ with the vertical. What is the change in momentum of the body along the Y- axis; between the starting point and the highest point of its path?

$$\mathrm{A}\:\mathrm{body}\:\mathrm{of}\:\mathrm{mass}\:\mathrm{m}\:\mathrm{is}\:\mathrm{projected}\:\mathrm{with}\:\mathrm{a} \\ $$$$\mathrm{speed}\:{v}\:\mathrm{making}\:\mathrm{an}\:\mathrm{angle}\:\theta\:\mathrm{with}\:\mathrm{the} \\ $$$$\mathrm{vertical}.\:\mathrm{What}\:\mathrm{is}\:\mathrm{the}\:\mathrm{change}\:\mathrm{in} \\ $$$$\mathrm{momentum}\:\mathrm{of}\:\mathrm{the}\:\mathrm{body}\:\mathrm{along}\:\mathrm{the}\:\mathrm{Y}- \\ $$$$\mathrm{axis};\:\mathrm{between}\:\mathrm{the}\:\mathrm{starting}\:\mathrm{point}\:\mathrm{and}\:\mathrm{the} \\ $$$$\mathrm{highest}\:\mathrm{point}\:\mathrm{of}\:\mathrm{its}\:\mathrm{path}? \\ $$

Question Number 16152    Answers: 1   Comments: 0

In long jump, does it matter how high you jump? What factors determine the span of the jump?

$$\mathrm{In}\:\mathrm{long}\:\mathrm{jump},\:\mathrm{does}\:\mathrm{it}\:\mathrm{matter}\:\mathrm{how}\:\mathrm{high} \\ $$$$\mathrm{you}\:\mathrm{jump}?\:\mathrm{What}\:\mathrm{factors}\:\mathrm{determine}\:\mathrm{the} \\ $$$$\mathrm{span}\:\mathrm{of}\:\mathrm{the}\:\mathrm{jump}? \\ $$

Question Number 16150    Answers: 1   Comments: 1

A projectile is fired at an angle θ with the horizontal direction from O. Neglecting the air friction, it hits the ground at B after 3 seconds. What is the height of point A from ground? [Use g = 10 m/s^2 ]

$$\mathrm{A}\:\mathrm{projectile}\:\mathrm{is}\:\mathrm{fired}\:\mathrm{at}\:\mathrm{an}\:\mathrm{angle}\:\theta\:\mathrm{with} \\ $$$$\mathrm{the}\:\mathrm{horizontal}\:\mathrm{direction}\:\mathrm{from}\:{O}. \\ $$$$\mathrm{Neglecting}\:\mathrm{the}\:\mathrm{air}\:\mathrm{friction},\:\mathrm{it}\:\mathrm{hits}\:\mathrm{the} \\ $$$$\mathrm{ground}\:\mathrm{at}\:{B}\:\mathrm{after}\:\mathrm{3}\:\mathrm{seconds}.\:\mathrm{What}\:\mathrm{is} \\ $$$$\mathrm{the}\:\mathrm{height}\:\mathrm{of}\:\mathrm{point}\:{A}\:\mathrm{from}\:\mathrm{ground}? \\ $$$$\left[\mathrm{Use}\:{g}\:=\:\mathrm{10}\:\mathrm{m}/\mathrm{s}^{\mathrm{2}} \right] \\ $$

Question Number 16139    Answers: 2   Comments: 0

Path of the bomb released from an aeroplane moving with uniform velocity at certain height as observed by the pilot is (a) a straight line (b) a parabola (c) a circle (d) none of the above

$$\mathrm{Path}\:\mathrm{of}\:\mathrm{the}\:\mathrm{bomb}\:\mathrm{released}\:\mathrm{from}\:\mathrm{an} \\ $$$$\mathrm{aeroplane}\:\mathrm{moving}\:\mathrm{with}\:\mathrm{uniform} \\ $$$$\mathrm{velocity}\:\mathrm{at}\:\mathrm{certain}\:\mathrm{height}\:\mathrm{as}\:\mathrm{observed} \\ $$$$\mathrm{by}\:\mathrm{the}\:\mathrm{pilot}\:\mathrm{is} \\ $$$$\left({a}\right)\:\mathrm{a}\:\mathrm{straight}\:\mathrm{line} \\ $$$$\left({b}\right)\:\mathrm{a}\:\mathrm{parabola} \\ $$$$\left({c}\right)\:\mathrm{a}\:\mathrm{circle} \\ $$$$\left({d}\right)\:\mathrm{none}\:\mathrm{of}\:\mathrm{the}\:\mathrm{above} \\ $$

Question Number 16138    Answers: 0   Comments: 0

How many nodal planes are present in 4d_z^2 ?

$$\mathrm{How}\:\mathrm{many}\:\mathrm{nodal}\:\mathrm{planes}\:\mathrm{are}\:\mathrm{present}\:\mathrm{in} \\ $$$$\mathrm{4d}_{\mathrm{z}^{\mathrm{2}} } \:? \\ $$

Question Number 16137    Answers: 0   Comments: 0

For 2s orbital Ψ_r = (1/(√8))((z/a_0 ))^(3/2) (2 − ((zr)/a_0 ))e^(−((zr)/(2a_0 ))) then, hydrogen radial node will be at the distance of (1) a_0 (2) 2a_0 (3) (a_0 /2) (4) (a_0 /3)

$$\mathrm{For}\:\mathrm{2}{s}\:\mathrm{orbital}\:\Psi_{\mathrm{r}} \:=\:\frac{\mathrm{1}}{\sqrt{\mathrm{8}}}\left(\frac{\mathrm{z}}{\mathrm{a}_{\mathrm{0}} }\right)^{\frac{\mathrm{3}}{\mathrm{2}}} \left(\mathrm{2}\:−\:\frac{\mathrm{zr}}{\mathrm{a}_{\mathrm{0}} }\right)\mathrm{e}^{−\frac{\mathrm{zr}}{\mathrm{2a}_{\mathrm{0}} }} \\ $$$$\mathrm{then},\:\mathrm{hydrogen}\:\mathrm{radial}\:\mathrm{node}\:\mathrm{will}\:\mathrm{be}\:\mathrm{at} \\ $$$$\mathrm{the}\:\mathrm{distance}\:\mathrm{of} \\ $$$$\left(\mathrm{1}\right)\:\mathrm{a}_{\mathrm{0}} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{2a}_{\mathrm{0}} \\ $$$$\left(\mathrm{3}\right)\:\frac{\mathrm{a}_{\mathrm{0}} }{\mathrm{2}} \\ $$$$\left(\mathrm{4}\right)\:\frac{\mathrm{a}_{\mathrm{0}} }{\mathrm{3}} \\ $$

Question Number 16136    Answers: 1   Comments: 0

Photoelectric emission is observed from a surface when lights of frequency n_1 and n_2 incident. If the ratio of maximum kinetic energy in two cases is K : 1 then (Assume n_1 > n_2 ) threshold frequency is (1) (K − 1) × (Kn_2 − n_1 ) (2) ((Kn_1 − n_2 )/(1 − K)) (3) ((K − 1)/(Kn_1 − n_2 )) (4) ((Kn_2 − n_1 )/(K − 1))

$$\mathrm{Photoelectric}\:\mathrm{emission}\:\mathrm{is}\:\mathrm{observed}\:\mathrm{from} \\ $$$$\mathrm{a}\:\mathrm{surface}\:\mathrm{when}\:\mathrm{lights}\:\mathrm{of}\:\mathrm{frequency}\:{n}_{\mathrm{1}} \\ $$$$\mathrm{and}\:{n}_{\mathrm{2}} \:\mathrm{incident}.\:\mathrm{If}\:\mathrm{the}\:\mathrm{ratio}\:\mathrm{of}\:\mathrm{maximum} \\ $$$$\mathrm{kinetic}\:\mathrm{energy}\:\mathrm{in}\:\mathrm{two}\:\mathrm{cases}\:\mathrm{is}\:\mathrm{K}\::\:\mathrm{1} \\ $$$$\mathrm{then}\:\left(\mathrm{Assume}\:{n}_{\mathrm{1}} \:>\:{n}_{\mathrm{2}} \right)\:\mathrm{threshold} \\ $$$$\mathrm{frequency}\:\mathrm{is} \\ $$$$\left(\mathrm{1}\right)\:\left(\mathrm{K}\:−\:\mathrm{1}\right)\:×\:\left(\mathrm{K}{n}_{\mathrm{2}} \:−\:{n}_{\mathrm{1}} \right) \\ $$$$\left(\mathrm{2}\right)\:\frac{\mathrm{K}{n}_{\mathrm{1}} \:−\:{n}_{\mathrm{2}} }{\mathrm{1}\:−\:\mathrm{K}} \\ $$$$\left(\mathrm{3}\right)\:\frac{\mathrm{K}\:−\:\mathrm{1}}{\mathrm{K}{n}_{\mathrm{1}} \:−\:{n}_{\mathrm{2}} } \\ $$$$\left(\mathrm{4}\right)\:\frac{\mathrm{K}{n}_{\mathrm{2}} \:−\:{n}_{\mathrm{1}} }{\mathrm{K}\:−\:\mathrm{1}} \\ $$

Question Number 16135    Answers: 0   Comments: 0

An electron is moving in 3^(rd) orbit of Hydrogen atom. The frequency of moving electron is (1) 2.19 × 10^(14) rps (2) 7.3 × 10^(14) rps (3) 2.44 × 10^(14) rps (4) 7.3 × 10^(10) rps

$$\mathrm{An}\:\mathrm{electron}\:\mathrm{is}\:\mathrm{moving}\:\mathrm{in}\:\mathrm{3}^{\mathrm{rd}} \:\mathrm{orbit}\:\mathrm{of} \\ $$$$\mathrm{Hydrogen}\:\mathrm{atom}.\:\mathrm{The}\:\mathrm{frequency}\:\mathrm{of} \\ $$$$\mathrm{moving}\:\mathrm{electron}\:\mathrm{is} \\ $$$$\left(\mathrm{1}\right)\:\mathrm{2}.\mathrm{19}\:×\:\mathrm{10}^{\mathrm{14}} \:\mathrm{rps} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{7}.\mathrm{3}\:×\:\mathrm{10}^{\mathrm{14}} \:\mathrm{rps} \\ $$$$\left(\mathrm{3}\right)\:\mathrm{2}.\mathrm{44}\:×\:\mathrm{10}^{\mathrm{14}} \:\mathrm{rps} \\ $$$$\left(\mathrm{4}\right)\:\mathrm{7}.\mathrm{3}\:×\:\mathrm{10}^{\mathrm{10}} \:\mathrm{rps} \\ $$

Question Number 16134    Answers: 0   Comments: 0

The mathematical expression which is true for the uncertainty principle is (1) (Δx) (Δv) ≥ (h/(4π)) (2) (ΔE) (Δx) ≥ (h/(4π)) (3) (Δθ) (Δφ) ≥ (h/(4π)) (4) (Δx) (Δm) ≥ (h/(4π))

$$\mathrm{The}\:\mathrm{mathematical}\:\mathrm{expression}\:\mathrm{which} \\ $$$$\mathrm{is}\:\mathrm{true}\:\mathrm{for}\:\mathrm{the}\:\mathrm{uncertainty}\:\mathrm{principle}\:\mathrm{is} \\ $$$$\left(\mathrm{1}\right)\:\left(\Delta{x}\right)\:\left(\Delta{v}\right)\:\geqslant\:\frac{\mathrm{h}}{\mathrm{4}\pi} \\ $$$$\left(\mathrm{2}\right)\:\left(\Delta\mathrm{E}\right)\:\left(\Delta{x}\right)\:\geqslant\:\frac{\mathrm{h}}{\mathrm{4}\pi} \\ $$$$\left(\mathrm{3}\right)\:\left(\Delta\theta\right)\:\left(\Delta\phi\right)\:\geqslant\:\frac{\mathrm{h}}{\mathrm{4}\pi} \\ $$$$\left(\mathrm{4}\right)\:\left(\Delta{x}\right)\:\left(\Delta\mathrm{m}\right)\:\geqslant\:\frac{\mathrm{h}}{\mathrm{4}\pi} \\ $$

Question Number 16133    Answers: 1   Comments: 0

H_α line of Balmer series is 6500 A^o . The wave length of Hγ is (1) 4815 A^o (2) 4298 A^o (3) 7800 A^o (4) 3800 A^o

$$\mathrm{H}_{\alpha} \:\mathrm{line}\:\mathrm{of}\:\mathrm{Balmer}\:\mathrm{series}\:\mathrm{is}\:\mathrm{6500}\:\overset{\mathrm{o}} {\mathrm{A}}.\:\mathrm{The} \\ $$$$\mathrm{wave}\:\mathrm{length}\:\mathrm{of}\:\mathrm{H}\gamma\:\mathrm{is} \\ $$$$\left(\mathrm{1}\right)\:\mathrm{4815}\:\overset{\mathrm{o}} {\mathrm{A}} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{4298}\:\overset{\mathrm{o}} {\mathrm{A}} \\ $$$$\left(\mathrm{3}\right)\:\mathrm{7800}\:\overset{\mathrm{o}} {\mathrm{A}} \\ $$$$\left(\mathrm{4}\right)\:\mathrm{3800}\:\overset{\mathrm{o}} {\mathrm{A}} \\ $$

Question Number 16102    Answers: 0   Comments: 0

Question Number 16081    Answers: 2   Comments: 0

A spherical balloon of 21 cm diameter is to be filled with hydrogen at NTP from a cylinder containing the gas at 20 atmosphere at 27°C. If the cylinder can hold 2.82 litres of water, calculate the number of balloons that can be filled up.

$$\mathrm{A}\:\mathrm{spherical}\:\mathrm{balloon}\:\mathrm{of}\:\mathrm{21}\:\mathrm{cm}\:\mathrm{diameter} \\ $$$$\mathrm{is}\:\mathrm{to}\:\mathrm{be}\:\mathrm{filled}\:\mathrm{with}\:\mathrm{hydrogen}\:\mathrm{at}\:\mathrm{NTP} \\ $$$$\mathrm{from}\:\mathrm{a}\:\mathrm{cylinder}\:\mathrm{containing}\:\mathrm{the}\:\mathrm{gas}\:\mathrm{at} \\ $$$$\mathrm{20}\:\mathrm{atmosphere}\:\mathrm{at}\:\mathrm{27}°\mathrm{C}.\:\mathrm{If}\:\mathrm{the}\:\mathrm{cylinder} \\ $$$$\mathrm{can}\:\mathrm{hold}\:\mathrm{2}.\mathrm{82}\:\mathrm{litres}\:\mathrm{of}\:\mathrm{water},\:\mathrm{calculate} \\ $$$$\mathrm{the}\:\mathrm{number}\:\mathrm{of}\:\mathrm{balloons}\:\mathrm{that}\:\mathrm{can}\:\mathrm{be} \\ $$$$\mathrm{filled}\:\mathrm{up}. \\ $$

Question Number 16044    Answers: 1   Comments: 1

A particle is projected horizontally with speed u from point A, which is 10 m above the ground. If the particle hits the inclined plane perpendicularly at point B. [g = 10 m/s^2 ] Find horizontal speed with which the particle was projected.

$$\mathrm{A}\:\mathrm{particle}\:\mathrm{is}\:\mathrm{projected}\:\mathrm{horizontally} \\ $$$$\mathrm{with}\:\mathrm{speed}\:{u}\:\mathrm{from}\:\mathrm{point}\:{A},\:\mathrm{which}\:\mathrm{is}\:\mathrm{10} \\ $$$$\mathrm{m}\:\mathrm{above}\:\mathrm{the}\:\mathrm{ground}.\:\mathrm{If}\:\mathrm{the}\:\mathrm{particle}\:\mathrm{hits} \\ $$$$\mathrm{the}\:\mathrm{inclined}\:\mathrm{plane}\:\mathrm{perpendicularly}\:\mathrm{at} \\ $$$$\mathrm{point}\:{B}.\:\left[{g}\:=\:\mathrm{10}\:\mathrm{m}/\mathrm{s}^{\mathrm{2}} \right] \\ $$$$\mathrm{Find}\:\mathrm{horizontal}\:\mathrm{speed}\:\mathrm{with}\:\mathrm{which}\:\mathrm{the} \\ $$$$\mathrm{particle}\:\mathrm{was}\:\mathrm{projected}. \\ $$

Question Number 16079    Answers: 1   Comments: 1

An open flask contains air at 27°C. To what temperature it must be heated to expel one-fourth of the air?

$$\mathrm{An}\:\mathrm{open}\:\mathrm{flask}\:\mathrm{contains}\:\mathrm{air}\:\mathrm{at}\:\mathrm{27}°\mathrm{C}.\:\mathrm{To} \\ $$$$\mathrm{what}\:\mathrm{temperature}\:\mathrm{it}\:\mathrm{must}\:\mathrm{be}\:\mathrm{heated}\:\mathrm{to} \\ $$$$\mathrm{expel}\:\mathrm{one}-\mathrm{fourth}\:\mathrm{of}\:\mathrm{the}\:\mathrm{air}? \\ $$

Question Number 16032    Answers: 0   Comments: 0

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