13753 + Interview Questions in Physics QA in Physics

1.	The force on the bullet which is fired from a gun is given by F =6-21 in N) wheretis in seconds. The force on the buliet becomes zero as it leaves the barrel. Theaverage impulse (in NS) imparted to the bullet is
Answer»

Discussion

2.	A wire is wound around a thin rod. It has 15 coils and it's length measures 2.5 cm. Calculate thediameter of the wire.
Answer»

Discussion

3.	AMPLE 13 lfa and Î˛ are the zeros ofthe polynomial f(x)-2-5x+ksuchthuto-$ÂŤLd the value of k.dare the reres of the polynomial f(x)-2-a+k
Answer»

Discussion

4.	60. A particle starts from rest and moves with a constantacceleration along a straight path to attain 64 m s-1 int s. If at t (t + 3)s the speed is 76 m s-1, th dthe acceleration of the particle and '.en tin
Answer» t is 16s and acc is 4m/s2

Discussion

5.	Why will a sheet of paperinto a ball?fallslowerthanonethรกtiscrumplec
Answer»

Discussion

6.	26.Why will a sheet of paper fall slower than one that is crumpled into a ball.
Answer»

Discussion

7.	. A particle of mass 'm' is suspended from aceiling through a string of length 'L'. If thparticle moves in a horizontal circle of radius'r' as shown in the figure, then the speed ofthe particle is(AP Eamcet-2016)
Answer»

Discussion

8.	1.Why are electric currents important?ndsenducters made of metals?
Answer» Direct current is seldom used as a primary energy source in industries. It mostly used in low voltage applications such as charging batteries, aircraft applications, etc. Alternating current is used to operate appliances for both household and industrial and commercial use. The electric current is measured in ampere.

Discussion

9.	D) At an angle of 135 wnh the direction of motion of car7. A gun fires rwo brullets at 60 and 30" with thehorizontal, the bullets strikes at some borizontal distanee. The ratio ofmaximum height for the two bullets isA) 2:1B) 3: 1C)4:1D) I I
Answer» The angles of two bullets from horizontal is 60 and 20 degrees and their velocity is also same. So, the height of two bullets is inthe ratio of their angles. Therefore,Height for the two bullet is in ratio 60 :30 =2 : 1

9.

D) At an angle of 135 wnh the direction of motion of car7. A gun fires rwo brullets at 60 and 30" with thehorizontal, the bullets strikes at some borizontal distanee. The ratio ofmaximum height for the two bullets isA) 2:1B) 3: 1C)4:1D) I I

Answer»

The angles of two bullets from horizontal is 60 and 20 degrees and their velocity is also same.

So, the height of two bullets is inthe ratio of their angles.

Therefore,Height for the two bullet is in ratio 60 :30 =2 : 1

Discussion

10.	16. Two bullets are fired horizontally with different velocities from the same height. Which will reach the ground first?A) Slower oneB) Faster oneD) It cannot be predictedBoth will reach simultaneouly
Answer» both will hit the ground simultaneously because the downward acceleration and initial velocities in the downward direction of the two bullets are same , they will take the same time to hit the ground and for half a projectile

Discussion

11.	OZ EXERCISER22123202ORANT B2Vnd out potential difference between point A and3.5 V54V(2) 3 V(4) 5 V
Answer» 4) is the correct answer (a) 3.5Vis a correct answer hello friend I HOPE SO "C" IS THE CORRECT ANSWER

11.

OZ EXERCISER22123202ORANT B2Vnd out potential difference between point A and3.5 V54V(2) 3 V(4) 5 V

Answer»

4) is the correct answer

(a) 3.5Vis a correct answer

hello friend

I HOPE SO

"C" IS THE CORRECT ANSWER

Discussion

12.	16. Two bullets are fired horizontally with different velocities from the same height. Which will reach the ground first?A) Slower oneBoth will reach simultaneoulyB) Faster oneD) It cannot be predicted
Answer» Both of them will hit the ground at the same time. This is because initially both of them have the same velocity in the y direction initially (which will also be the velocity of the plane in the y direction). The acceleration acting on both bullets will be the same (g). The trajectories will be different, but they will hit the ground at exactly the same time. Of course, there are a few assumptions here that I make. Like there is no air resistance, the bullets are fired from the same level and the ground is flat.

12.

16. Two bullets are fired horizontally with different velocities from the same height. Which will reach the ground first?A) Slower oneBoth will reach simultaneoulyB) Faster oneD) It cannot be predicted

Answer»

Both of them will hit the ground at the same time.

This is because initially both of them have the same velocity in the y direction initially (which will also be the velocity of the plane in the y direction). The acceleration acting on both bullets will be the same (g). The trajectories will be different, but they will hit the ground at exactly the same time.

Of course, there are a few assumptions here that I make. Like there is no air resistance, the bullets are fired from the same level and the ground is flat.

Discussion

13.	4. A 10 ohm thick wire is stretched so that its lengthbecomes three times. Assuming that there is nochange in density on stretching, calculate the resistanceAns : 90 ohmjof the new wire.
Answer» Resistance ‘R = 10 ohm’ is related to length ‘L’, area of cross-section ‘A’ and resistivity ‘ρ’ as, R = ρL/A When L is tripled , As we know that the volume of the wire remains same. old volume = new volume AL = A'L' ....(i) ( as volume = area x length ) L' = 3L So, from (i) A' = A/3 So the new resistance is , R' = ρL'/A' or R' = ρ(3L)/(A/3) = 9 (ρL/A) => R' = 9R so, the new resistance increases nine fold. Now, R' = 9 x 10ohms thus, R' = 90 ohms

13.

4. A 10 ohm thick wire is stretched so that its lengthbecomes three times. Assuming that there is nochange in density on stretching, calculate the resistanceAns : 90 ohmjof the new wire.

Answer»

Resistance ‘R = 10 ohm’ is related to length ‘L’, area of cross-section ‘A’ and resistivity ‘ρ’ as,

R = ρL/A

When L is tripled ,

As we know that the volume of the wire remains same.

old volume = new volume

AL = A'L' ....(i) ( as volume = area x length )

L' = 3L

So, from (i)

A' = A/3

So the new resistance is ,

R' = ρL'/A'

or

R' = ρ(3L)/(A/3) = 9 (ρL/A)

=> R' = 9R

so, the new resistance increases nine fold.

Now,

R' = 9 x 10ohms

thus,

R' = 90 ohms

Discussion

14.	4. A 10 ohm thick wire is stretched so that its lengthbecomes three times. Assuming that there is nochange in density on stretching, calculate the resistanceAns 90 ohm]of the new wire.
Answer» Resistance ‘R = 10 ohm’ is related to length ‘L’, area of cross-section ‘A’ and resistivity ‘ρ’ as,R = ρL/AWhen L is tripled ,As we know that the volume of the wire remains same.old volume = new volumeAL = A'L' ....(i) ( as volume = area x length )L' = 3LSo, from (i)A' = A/3So the new resistance is ,R' = ρL'/A'orR' = ρ(3L)/(A/3) = 9 (ρL/A)=> R' = 9Rso, the new resistance increases nine fold.Now,R' = 9 x 10ohmsthus,R' = 90 ohms

Discussion

15.	One end of a horizontal thick co2R is welded to an end of another horizontal thilength L and radius R. When the arrangement is stretchetsapplying forces at two ends, the ratio of the elongation in tewire to that in the thick wire is(a) 0.25(c) 2.00pper wire of length 21copper winein the[JEE (Advanced) 2013(b) 0.50(d) 4.00mgl formula would give Y if mgis doubled
Answer» = F/π(2R)2/∆ℓ12L = F/πR2/∆ℓ2/L ∴ ∆ℓ2/∆ℓ1= 2

15.

One end of a horizontal thick co2R is welded to an end of another horizontal thilength L and radius R. When the arrangement is stretchetsapplying forces at two ends, the ratio of the elongation in tewire to that in the thick wire is(a) 0.25(c) 2.00pper wire of length 21copper winein the[JEE (Advanced) 2013(b) 0.50(d) 4.00mgl formula would give Y if mgis doubled

Answer»

= F/π(2R)2/∆ℓ12L = F/πR2/∆ℓ2/L

∴ ∆ℓ2/∆ℓ1= 2

Discussion

16.	One end of a horizontal thick copper wire of lengh 2L2R is welded to an end of another horizontathin copper witeh L and radius R. When the arrangement is stetcheapplying forces at two ends, the ratio ofwire to that in the thick wire is(a) 0.25(c) 2.00the elongation in tetJEE (Advanced) 2018(b) 0.50(d) 4.00Y=mg-formula would give Y if mg is doubledr 2L[MP PMT 2009,1M
Answer» F/π(2R)2/∆ℓ12L = F/πR2/∆ℓ2/L ∴ ∆ℓ2/∆ℓ1= 2option c

16.

One end of a horizontal thick copper wire of lengh 2L2R is welded to an end of another horizontathin copper witeh L and radius R. When the arrangement is stetcheapplying forces at two ends, the ratio ofwire to that in the thick wire is(a) 0.25(c) 2.00the elongation in tetJEE (Advanced) 2018(b) 0.50(d) 4.00Y=mg-formula would give Y if mg is doubledr 2L[MP PMT 2009,1M

Answer»

F/π(2R)2/∆ℓ12L = F/πR2/∆ℓ2/L

∴ ∆ℓ2/∆ℓ1= 2option c

Discussion

17.	coils of electric toasters and electric irons made of an alloyrather than a pure metal?
Answer»

Discussion

18.	Why are coils of electric toasters and electric irons made of an alloyrather than a pure metal?
Answer»

Discussion

19.	A vector is multiplied by a pure real number. Will itsunit change?
Answer» yes it will change ok

Discussion

20.	he ratio of diameters of two wires of samematerial is n:1. The length of each wire is 4m.On applying the same load, increase in lengthof the thin wire will be (n>1)
Answer»

Discussion

21.	The ratio of diameters of two wires of samematerial is n:1. The length of each wire is 4m.Onapplying the same load, increase in lengthof the thin wire will be (n>1)
Answer»

Discussion

22.	16·A) Draw a schematic diagram of a circuit consisting of a battery of five 2V cells, a 5 ohm resistor,a 10 ohm resistor and a 15 ohm resistor, and a plug key, all are connected in series.(ii) Calculate the electric current passing through the above circuit when the key is closed.
Answer»

Discussion

23.	38.TheC.G.of a taxi is 1.5 m above the round and the distance between itswheels is 2 m. What is the maximum speed with which it can go round anunbanked curve of radius 100 m without being turned upside down? Whatminimum value of coefficient of friction would be required at this speed? (Ar
Answer» Like if you find it useful!

Discussion

24.	One end of a string of length 1.4 m is tied to a stone of mass 0.4 kg and th other end to a small pivot on a smoothvertical board. Calculate the minimum speed of the stone required at its lowest point so that the string dows notslacken at any point in its motion along the vertical circle?(Ans. 8.28 m s-1)
Answer»

Discussion

25.	iginar uistanitce berween them ?On a two-lane road, car A is travelling with a speed of 36 km h-1. Two cars B andC approach car A in opposite directions with a speed of 54 km heach. At acertain instant, when the distance AB is equal to AC, both being 1 km, B decidesto overtake A before C does. What minimum acceleration of car B is required toavoid an accident ?
Answer»

Discussion

26.	8 On a two-lane road, car A is travelling with a speed of 36 kmh-1.TwocarsBandC approach car A in opposite directions with a speed of 54 km heach. At acertain instant, when the distance AB is equal to AC, both being 1 km, B decidesto overtake A before C does. What minimum acceleration of car B is required toavold an accident?
Answer»

Discussion

27.	Pre-Medical: PhysicsA disc of mass 1.0kgis kept floating horizontally inair by firing bullets of mass 0:05 kg each verticallyat it, at the rate of 10per second. If the bulletsrebound with the same speed, the speed with whichthese are fired will be-Mg
Answer» jhchchxuddjsbjxixxhhsbbsnssiixixixujxbdbdb yhfjfndndnnsnenenekekeodjxnbdbdbdbdnndkdk

27.

Pre-Medical: PhysicsA disc of mass 1.0kgis kept floating horizontally inair by firing bullets of mass 0:05 kg each verticallyat it, at the rate of 10per second. If the bulletsrebound with the same speed, the speed with whichthese are fired will be-Mg

Answer»

jhchchxuddjsbjxixxhhsbbsnssiixixixujxbdbdb

yhfjfndndnnsnenenekekeodjxnbdbdbdbdnndkdk

Discussion

28.	Two thin planks are moving on a four identical cylinder asshown. There is no slipping at any contact points.Calculate the ratio of angular speed of upper cylinder tolower cylinder.2VR+
Answer»

Discussion

29.	3.In which one of the given figures, is the function diode forward biased ?v4 +2vova 2--2v 4 or*+2V +5v
Answer»

Discussion

30.	1923320CURRENT BOZ-BRERSERАв10320'2VFind out potential difference between point A and(1) 3.5 V(3) 4 V(2) 3 V(4) 5 V
Answer» Here Option A is right this answer is 1-3.5v

30.

1923320CURRENT BOZ-BRERSERАв10320'2VFind out potential difference between point A and(1) 3.5 V(3) 4 V(2) 3 V(4) 5 V

Answer»

Here Option A is right

this answer is 1-3.5v

Discussion

31.	wwNNN2v2V2VIn the above circuit the current in each resistance is(a) 1 A(b) 0.25 A(c) 0.5 A(d) O A
Answer» t will be 0Opti on Das

Discussion

32.	WWW312w2v2V2v2V2VIn the above circuit the current in each resistance is(a) 1 A(b) 0.25 A(c) 0.5 A(d) O A
Answer» 0 A Option D

Discussion

33.	What is the work to be doneto increase the velocity of a car from30 km h1 to 60 km h1 if the mass ofthe car is 1500 kg?
Answer» Work = Change in kinetic energy = 0.5 m (v² - u²) = 0.5 × 1500 kg × [(60 × 5/18 m/s)² - (30 × 5/18 m/s)²] = 156250 joules = 156.25 kJ Work done is 156.25 kJ

33.

What is the work to be doneto increase the velocity of a car from30 km h1 to 60 km h1 if the mass ofthe car is 1500 kg?

Answer»

Work = Change in kinetic energy

= 0.5 m (v² - u²)

= 0.5 × 1500 kg × [(60 × 5/18 m/s)² - (30 × 5/18 m/s)²]

= 156250 joules

= 156.25 kJ

Work done is 156.25 kJ

Discussion

34.	3. A train starting from a railwaystution and moving with uniformacceleration attains a speed40 km h1 in 10 minutes. Find itsacceleration.
Answer» thankyou

Discussion

35.	xample 11.4 What is the work to be doto increase the velocity of a car fr30 km h1 to 60 km h- if the massthe car is 1500 kg?olution:
Answer» for velocity to be changed from 30km/h , to 60km/h change the velocity in m/s 30km/h = 305/18 = 25/3 m/s and 60km/h = (50/3) m/s the work done = change in K.E w = 1/2m((50/3)²-(25/3)²) = 1/2(1500)*(2500-625)/9 = 156250J = 156.25 KJ

35.

xample 11.4 What is the work to be doto increase the velocity of a car fr30 km h1 to 60 km h- if the massthe car is 1500 kg?olution:

Answer»

for velocity to be changed from 30km/h , to 60km/h change the velocity in m/s

30km/h = 30*5/18 = 25/3 m/s and 60km/h = (50/3) m/s

the work done = change in K.E

w = 1/2*m*((50/3)²-(25/3)²) = 1/2*(1500)*(2500-625)/9 = 156250J = 156.25 KJ

Discussion

36.	An electric iron consumes energy at a rate of 840 W when heating is at the maximum ratéwhen the heating is at the minimum. The voltage is 220 V. Weach case15.hat are the current and the resistance inNCERT)
Answer»

Discussion

37.	An electric iron consumes energy at a rate of 840 W when heatingis at the maximum rate and 360 W when the heating is at theminimum. The voltage is 220 V. What are the current and theresistance in each case?
Answer» When heating at max rate,power, P = 840WV = 220V We know P = VI⇒ 840 = 220× I⇒ I = 840/220⇒ I = 4A R = V/I = 220/4 = 55Ω So current = 4A and resistance = 55Ω When heating at minimum rate,power, P = 360WV = 220V We know P = VI⇒ 360 = 220× I⇒ I = 360/220⇒ I = 1.636A R = V/I = 220/1.636 = 134.45 Ω Socurrent = 1.636A and resistance = 134.45Ω Like my answer if you find it useful!

37.

An electric iron consumes energy at a rate of 840 W when heatingis at the maximum rate and 360 W when the heating is at theminimum. The voltage is 220 V. What are the current and theresistance in each case?

Answer»

When heating at max rate,power, P = 840WV = 220V

We know P = VI⇒ 840 = 220× I⇒ I = 840/220⇒ I = 4A

R = V/I = 220/4 = 55Ω

So current = 4A and resistance = 55Ω

When heating at minimum rate,power, P = 360WV = 220V

We know P = VI⇒ 360 = 220× I⇒ I = 360/220⇒ I = 1.636A

R = V/I = 220/1.636 = 134.45 Ω

Socurrent = 1.636A and resistance = 134.45Ω

Like my answer if you find it useful!

Discussion

38.	Example 12.10An electric iron consumes energy at a rate of 840 W when heatingis at the maximum rate and 360 W when the heating is at theminimum. The voltage is 220 V. What are the current and theresistance in each case?
Answer»

Discussion

39.	N836) A brass boiler has a base area of 0.15 m2 and thickness 1 cm. It boils water at the rateof 6 kg/min, when placed on a gas stove. Estimate the temperature of the part of theflame in contact with the boiler. Thermal conductivity of brass-109Wm'K-1 Latent hof vapourisation of water-22561g
Answer»

Discussion

40.	11.20A brass boiler has a base area of 0.15 m2 and thickness 1.0 cm. It boils water at therate of 6.0 kg/min when placed on a gas stove. Estimate the temperature of the part
Answer»

Discussion

41.	What happens to the medium through which sound travels
Answer» Sound waves need to travel through a medium such as a solid, liquid, or gas. The sound waves move through each of these mediums by vibrating the molecules in the matter.

Discussion

42.	3292ORANT GROTEXERCISERLABw3202nd out potential difference between point A and3.5 V4V(2) 3 V(4) 5 V
Answer»

Discussion

43.	323212TABORANT ELFOZ EREROS2Vnd out potential difference between point A and3.5 V4V(2) 3 v(4) 5 V
Answer» 3.5 is the best and correct answer of your question. Please give me just one thanks to Reedom rewards and getting amazing vouchers.

Discussion

44.	19WORINT BEVOZ-EXERCISEAU3292Ав193202Find out potential difference between point A and(1) 3.5 V(3) 4 V(2) 3 V(4) 5 V
Answer» Option-a

Discussion

45.	3292URANT BOZ EXERCISELAB322Wnd out potential difference between point A and3.5 V4v(2) 3 v(4) 5 V
Answer»

Discussion

46.	252RENT BOZ EXERCISELAB23$20HTnd out potential difference between point A and3.5 V40(2) 3 v(4) 5 V
Answer»

Discussion

47.	1. A bus starts from rest and attains 40 kmhin (1) km h-2 and (ii) ms?velocity after 10 seconds. Calculate the acceleration of the busAns.( 14400 km2
Answer» We know,v = u + at v = final velocityu = initial velocitya = accelerationt = time t = 10 sec = 10/3600 hr 40 = 0 + a(1/360) a = 40360 = 14400 km/hr^2 In m/s^2a = 14400 * 1000/(36003600) = 14400 (1/18*720) = 1.11 m/s^2

47.

1. A bus starts from rest and attains 40 kmhin (1) km h-2 and (ii) ms?velocity after 10 seconds. Calculate the acceleration of the busAns.( 14400 km2

Answer»

We know,v = u + at

v = final velocityu = initial velocitya = accelerationt = time

t = 10 sec = 10/3600 hr

40 = 0 + a*(1/360)

a = 40*360 = 14400 km/hr^2

In m/s^2a = 14400 * 1000/(3600*3600) = 14400 * (1/18*720) = 1.11 m/s^2

Discussion

48.	A bicycle increases its speed frorn 10 km/h to 15 km/h in 6 seconds. Calculate its acceleration
Answer» Initial velocity = u = 10 km /hr = 10 x 5 /18= 2.77777= 2.8 m /s Final velocity = v = 15 km / hr= 15 x 5 / 18= 4.16 m /s [ approx .] Time = t = 6 sec a = acceleration Equation of motion : v = u + at 4.16 = 2.8 + 6a 6a + 2.8 = 4.16 6a = 4.16 - 2.8 6a = 1.36 a = 1.36 / 6 a = 0.22 m /s²

48.

A bicycle increases its speed frorn 10 km/h to 15 km/h in 6 seconds. Calculate its acceleration

Answer»

Initial velocity = u = 10 km /hr = 10 x 5 /18= 2.77777= 2.8 m /s

Final velocity = v = 15 km / hr= 15 x 5 / 18= 4.16 m /s [ approx .]

Time = t = 6 sec

a = acceleration

Equation of motion :

v = u + at

4.16 = 2.8 + 6a

6a + 2.8 = 4.16

6a = 4.16 - 2.8

6a = 1.36

a = 1.36 / 6

a = 0.22 m /s²

Discussion

49.	28. A cheetah starts from rest, and accelerates at 2 m/s2 for 10 seconds. Calculate :(a) the final velocity(h) the distance travelled.
Answer»

Discussion

50.	3. A bicycle increases its speed from 10 km/h to 15 km/h in 6 seconds. Calculate its accele-ration.
Answer»

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The force on the bullet which is fired from a gun is given by F =6-21 in N) wheretis in seconds. The force on the buliet becomes zero as it leaves the barrel. Theaverage impulse (in NS) imparted to the bullet is

A wire is wound around a thin rod. It has 15 coils and it's length measures 2.5 cm. Calculate thediameter of the wire.

AMPLE 13 lfa and Î˛ are the zeros ofthe polynomial f(x)-2-5x+ksuchthuto-$ÂŤLd the value of k.dare the reres of the polynomial f(x)-2-a+k

60. A particle starts from rest and moves with a constantacceleration along a straight path to attain 64 m s-1 int s. If at t (t + 3)s the speed is 76 m s-1, th dthe acceleration of the particle and '.en tin

Why will a sheet of paperinto a ball?fallslowerthanonethรกtiscrumplec

26.Why will a sheet of paper fall slower than one that is crumpled into a ball.

. A particle of mass 'm' is suspended from aceiling through a string of length 'L'. If thparticle moves in a horizontal circle of radius'r' as shown in the figure, then the speed ofthe particle is(AP Eamcet-2016)

1.Why are electric currents important?ndsenducters made of metals?

D) At an angle of 135 wnh the direction of motion of car7. A gun fires rwo brullets at 60 and 30" with thehorizontal, the bullets strikes at some borizontal distanee. The ratio ofmaximum height for the two bullets isA) 2:1B) 3: 1C)4:1D) I I

16. Two bullets are fired horizontally with different velocities from the same height. Which will reach the ground first?A) Slower oneB) Faster oneD) It cannot be predictedBoth will reach simultaneouly

OZ EXERCISER22123202ORANT B2Vnd out potential difference between point A and3.5 V54V(2) 3 V(4) 5 V

16. Two bullets are fired horizontally with different velocities from the same height. Which will reach the ground first?A) Slower oneBoth will reach simultaneoulyB) Faster oneD) It cannot be predicted

4. A 10 ohm thick wire is stretched so that its lengthbecomes three times. Assuming that there is nochange in density on stretching, calculate the resistanceAns : 90 ohmjof the new wire.

4. A 10 ohm thick wire is stretched so that its lengthbecomes three times. Assuming that there is nochange in density on stretching, calculate the resistanceAns 90 ohm]of the new wire.

coils of electric toasters and electric irons made of an alloyrather than a pure metal?

Why are coils of electric toasters and electric irons made of an alloyrather than a pure metal?

A vector is multiplied by a pure real number. Will itsunit change?

he ratio of diameters of two wires of samematerial is n:1. The length of each wire is 4m.On applying the same load, increase in lengthof the thin wire will be (n&gt;1)

The ratio of diameters of two wires of samematerial is n:1. The length of each wire is 4m.Onapplying the same load, increase in lengthof the thin wire will be (n&gt;1)

16·A) Draw a schematic diagram of a circuit consisting of a battery of five 2V cells, a 5 ohm resistor,a 10 ohm resistor and a 15 ohm resistor, and a plug key, all are connected in series.(ii) Calculate the electric current passing through the above circuit when the key is closed.

38.TheC.G.of a taxi is 1.5 m above the round and the distance between itswheels is 2 m. What is the maximum speed with which it can go round anunbanked curve of radius 100 m without being turned upside down? Whatminimum value of coefficient of friction would be required at this speed? (Ar

Pre-Medical: PhysicsA disc of mass 1.0kgis kept floating horizontally inair by firing bullets of mass 0:05 kg each verticallyat it, at the rate of 10per second. If the bulletsrebound with the same speed, the speed with whichthese are fired will be-Mg

Two thin planks are moving on a four identical cylinder asshown. There is no slipping at any contact points.Calculate the ratio of angular speed of upper cylinder tolower cylinder.2VR+

3.In which one of the given figures, is the function diode forward biased ?v4 +2vova 2--2v 4 or*+2V +5v

1923320CURRENT BOZ-BRERSERАв10320'2VFind out potential difference between point A and(1) 3.5 V(3) 4 V(2) 3 V(4) 5 V

wwNNN2v2V2VIn the above circuit the current in each resistance is(a) 1 A(b) 0.25 A(c) 0.5 A(d) O A

WWW312w2v2V2v2V2VIn the above circuit the current in each resistance is(a) 1 A(b) 0.25 A(c) 0.5 A(d) O A

What is the work to be doneto increase the velocity of a car from30 km h1 to 60 km h1 if the mass ofthe car is 1500 kg?

3. A train starting from a railwaystution and moving with uniformacceleration attains a speed40 km h1 in 10 minutes. Find itsacceleration.

xample 11.4 What is the work to be doto increase the velocity of a car fr30 km h1 to 60 km h- if the massthe car is 1500 kg?olution:

An electric iron consumes energy at a rate of 840 W when heating is at the maximum ratéwhen the heating is at the minimum. The voltage is 220 V. Weach case15.hat are the current and the resistance inNCERT)

An electric iron consumes energy at a rate of 840 W when heatingis at the maximum rate and 360 W when the heating is at theminimum. The voltage is 220 V. What are the current and theresistance in each case?

Example 12.10An electric iron consumes energy at a rate of 840 W when heatingis at the maximum rate and 360 W when the heating is at theminimum. The voltage is 220 V. What are the current and theresistance in each case?

N836) A brass boiler has a base area of 0.15 m2 and thickness 1 cm. It boils water at the rateof 6 kg/min, when placed on a gas stove. Estimate the temperature of the part of theflame in contact with the boiler. Thermal conductivity of brass-109Wm'K-1 Latent hof vapourisation of water-22561g

11.20A brass boiler has a base area of 0.15 m2 and thickness 1.0 cm. It boils water at therate of 6.0 kg/min when placed on a gas stove. Estimate the temperature of the part

What happens to the medium through which sound travels

3292ORANT GROTEXERCISERLABw3202nd out potential difference between point A and3.5 V4V(2) 3 V(4) 5 V

323212TABORANT ELFOZ EREROS2Vnd out potential difference between point A and3.5 V4V(2) 3 v(4) 5 V

19WORINT BEVOZ-EXERCISEAU3292Ав193202Find out potential difference between point A and(1) 3.5 V(3) 4 V(2) 3 V(4) 5 V

3292URANT BOZ EXERCISELAB322Wnd out potential difference between point A and3.5 V4v(2) 3 v(4) 5 V

252RENT BOZ EXERCISELAB23$20HTnd out potential difference between point A and3.5 V40(2) 3 v(4) 5 V

1. A bus starts from rest and attains 40 kmhin (1) km h-2 and (ii) ms?velocity after 10 seconds. Calculate the acceleration of the busAns.( 14400 km2

A bicycle increases its speed frorn 10 km/h to 15 km/h in 6 seconds. Calculate its acceleration

28. A cheetah starts from rest, and accelerates at 2 m/s2 for 10 seconds. Calculate :(a) the final velocity(h) the distance travelled.

3. A bicycle increases its speed from 10 km/h to 15 km/h in 6 seconds. Calculate its accele-ration.

he ratio of diameters of two wires of samematerial is n:1. The length of each wire is 4m.On applying the same load, increase in lengthof the thin wire will be (n>1)

The ratio of diameters of two wires of samematerial is n:1. The length of each wire is 4m.Onapplying the same load, increase in lengthof the thin wire will be (n>1)