Physics Questions

The wires which connect the battery of an automobile to its starting motor carry a current of 300 A for a short time What is the force per unit length between the wires if they are 70 cm long and 1 5 cm apart Is the force attractive or repulsive 2 Points 1 2 N and Attraction 1 2 N and Repulsive 2 4 N and Attractive 2 4 N and Repulsive

A particle moving in a straight line covers half the distance with speed of 10 m s The other half of the distance is covered in two equal time intervals with speed of 4 5 m s and 7 5 m s respectively The average speed of the particle during this motion is 1 8 0 m s 3 10 0 m s 2 12 0 m s 4 7 5 m s

A particle moves in a circle of radius 4 cm clockwise at constant speed of 2 cm s If and y are unit acceleration vector along x and y directions respectively in cm sec The acceleration of the particle at the instant half way between P and Q is given by m 4 x y b 4 x y c QX x y 2 8 9 d 4 P U 20 5 Oc 2 0

Stewart kicks a soccer ball with initial velocity of 20 feet per second at an angle of 40 to the horizontal The parametric equation that describes the position of the ball as a function of time are 20 cos 40t y 16t 20 sin 40t If he is 25 feet away from a 5ft goal will the ball go in O No The ball will bounce first No The ball will be at a height of 24 ft Yes The ball will be at a height of 24 ft Yes The ball will go in

7 Stress strain curve for four metals are shown in figure The maximum young modulus of elasticity is for meta Strain 1 A 3 C Stress 2 B 4 D

6 Steam at 100 C is passed into 20 g of water at 10 C When water acquires a temperature of 80 C the mass of water present will be 008 1 Take specific heat of water 1 cal g C 1 and latent heat of steam 540 cal g AIPMT 2014 1 24 g 3 42 5 g and 2 31 5 g 0216 Yeunivers 4 22 5 g

nderstand the previous explaination A drop of water of mass m and density p is placed between two well cleaned glass plates the distance between which is d What is the force of attraction between the plates T surface tension A B Tm 2pd C 4Tm pd 27m pd Tm D pd Your Answer D Correct Answer I Donorintion

g 9 8 m s A body is thrown vertically upwards with a velocity of 49 m s Find the time that passes between the instants when it goes past a point 100 m from the ground in its upward and downward journey g 9 8 m s 4 28 s

When the angular velocity of a uniformly rotating body has increased thrice the resultant of forces applied to it increases by 60 newton Find the accelerations of the body in the two cases The mass of the body m 3 kg a 2 5 ms 2 7 5 ms 2 c 5 ms 2 45 ms b 7 5 ms 2 22 5 ms d 2 5 ms 2 22 5 ms 2

Two identical metallic spheres having charge 6Q and 2Q are placed r distance apart from their centres Force of attraction between them is F After that if they are brought in contact and then placed at the same distance r New force acting on them is a F 2 b F 3 c F 6 d F 4

An LCR series circuit connected across a source of alternating emf E is in resonance Then the voltage across 1 R is zero 2 R equals to applied voltage zero 3 C is zero 4 Lequals to applied voltage

If d d 0 then select correct option 1 The charge in the vicinity of the surface may be zero 2 The electric field must be zero on the surface 3 The net charge inside the surface must not be 4 zero 4 Net electric flux through surface may not be zero

What is the distance of the image of the point object O from the surface of water in the diagram shown below where bottom of the container is silver polished 12 cm 1 30 cm 2 34 cm 3 20 cm 4 15 cm O 16 cm What is the distance of the image of the int object from the surface of water in e diagram shown below where bottom the container is silver polished 16 cm cm WA 1 30 cm 2 34 cm 3 20 cm 4 cm

Example 13 A steel wire 4 0 m in length is stretched through 2 0 mm The cross sectional area of the wire i 2 0 mm If Young s modulus of steel is 2 0 10 Nm2 Find m 6Y The energy density of wire The plastic potential in the wim

ball is placed on a smooth inclined plane of inclination 0 30 to the horizontal which is ating at frequency 0 5 Hz about a vertical axis passing through its lower end At what tance from the lower end does the ball remain at rest 1 85 m b 0 2 m c 0 42 m d 0 67 m

BOAL BOVNCERT BASEDOBJECTIVE PHY3 MOTIONINASTRAIGHT UNE P65 11 x m 2 4 6 8 10 12 14 16 18 20 22 t What is nature of acceleration from t t 10 sec in above diagram 1 Positive 3 Zero 2 Negative 4 None of th

A If the force of gravitation is inversely proportional to the distance r rather than 2 given by Newton then orbital velocity of the satellite around the earth is independent of r R GMm mv r so v GM

The maximum current that can be measured by a galvanometer of resistance 40 is 10 mA It is converted into voltmeter that can read upto 50 V The resistance to be connected in the series with the galvanometer is 2 Points 2010 2 4050 5040 S 4060 O

A bimetallic strip consists of metals A and B It is mounted rigidly as shown The metal A has higher coefficient of expansion compared to that of metal B When the bimetallic strip is placed in both it will 1 2 ect Answer 4 sunattempted Bend towards the right Not bend but shrink Neither bend nor shrink Bend towards the left AB

From the equation tan 0 rg one can obtain the angle of banking 0 from vertical for cyclist taking a curve the symbols have the usual meanings The equation is 1 both dimensionally and numerically corre 2 neither numerically nor dimensional correct 3 dimensionally correct only 4 numerically correct only

13 A highly conducting cylindrical vessel placed on elevated small supports contains an ideal gas under a piston of mass m Area of the base of the cylinder is A The piston is in equilibrium in the mid of the cylinder Friction force between the cylinder and the piston can be ignored Total mass of the cylinder and the gas is M The atmospheric pressure is po Now the piston is slowly pulled upwards find the maximum value of M such that the cylinder can be lifted off the supports PA mg a b c 2p A mg 2g PA mg 2g d It is impossible in this way

of the above Which of the following is the most precis instrument for measuring length 1 Metre rod of least count 0 1 cm 2 Vernier callipers of least count 0 01 cm 3 Screw gauge of least count 0 001 cm 4 Data is not sufficient to decide

Two bodies of masses 1kg 10 kg are dropped from the top of a tower On the surface of earth simultaneously 1 Heavier will reach first 2 Lighter will reach first 3 Both will reach simultaneously 4 Any one will reach first

3 In the given figure the network R 2 2 and E 12 V The equivalent resistance of the above network and current through each branch of the network is a 4 2 and 2 5 A respectively e 2 2 and 6 A respectively b 2 2 and 3 A respectively d None of the above

Suppose true value of certain length is near 3 3 578 cm student took three reading with different scale a 3 5 cm using 0 1 cm resolution scale b 3 38 cm using 0 01 cm resolution scale c 3 372 cm using 0 001 cm resolution scale then 1 First is more accurate 2 2nd is more accurate 3 3rd is more precise 4 Both 1 and 3 are correct

You do a very precise experiment to test the properties of a piece of wire You stretch the wire by applying an outward force to each end of the wire and measure its change in length If you then precisely double this force and the wire still remains elastic but is beyond proportionality limit the change in length of the wire 1 will exactly double 49 2 will just slightly more than double 3 will just slightly less than double 4 will decrease by exactly a factor of two

N molecules each of mass m of gas A and 2N molecules each of mass 2m of gas B are contained in the same vessel at temperature T The mean square of the velocity of molecules of gas B is velocity of molecules of gas A is and the mean square of x component of the 2 The ratio 1 1 3 2 2 is 4

A ball is thrown from a point at different angles with same speed u and has same range in both cases If h and h are the heights attained in the two cases then h h will be 2u u 2 9 9 b 2g d 4g

50 A circular coil of one turn is made of a wire of certain length and then from the same length a coil of three turns is made If same current is passed in both the cases then the ratio of magnetic inductions at their centres in both the cases respectively is 1 3 1 3 9 1 2 1 9 4 1 3 N N

5 Check the correctness of the relation S ut at where u is initial veloci acceleration t the time and S the displ 1 Dimensionally correct 2 Dimensionally incorrect 3 Can t explain 4 Data insufficient

If the mass of the Sun were ten times smaller and the universal gravitational constant were ten times larger in magnitude which of the following is not correct 1 Raindrops will fall faster 2 Walking on the ground would become more difficult 3 g on the Earth will not change 4 Time period of a simple pendulum on the Earth would decrease

Select the incorrect are 1 0 06900 has 4 number of significant figur 2 0 6900 has 4 number of significant figur 3 6 900 has 2 number of significant figu 4 6 900 kg has 4 number of significant figu

The monochromatic beam of light is incident at 60 on one face of an equilateral prism of refractive index n and emerges from the opposite face making an angle 8 n with the normal see the figure For n 3 the value of 0 is 60 de and m The value of m is dn 60 Correct answer 2

Add 6 75 x 10 cm to 4 52 x 10 cm with regard to significant figures 1 7 20 x 10 cm 3 7 20 x 104 cm 2 7 20 x 10 cm 4 720 cm gth of 217 cm and radiu

1 A cell of emf E in the secondary circuit gives null deflection for 1 5 m length of potentiometer of wire length 10 m If another cell of emf E2 is connected in series with E then the null deflection was obtained for 2 5 m length of potentiometer Then E E2 is 1 3 5 2 2 3 3 3 2 4 5 3 RK C

The centripetal force F acting on a particle 27 moving uniformly in a circle may depend upon mass m velocity v and radius r of the circle Derive the formula for F using the method of dimensions 1 F mv r mr 2 F my r mv

26 Write the dimensions of a in the relation P b x at where P is power x the distance and t the time 1 MOLOTO 2 M LOT2 3 M L T2 4 M LT 1 26

A thin wire has a length of 21 7 cm and radius 0 46 mm Calculate the volume of the wire to correct significant figures 1 0 14 cm 3 0 014 cm 2 0 144 cm 4 0 143 cm

A rigid ring A and a rigid thin disk B bo of same material when gently placed c just manage to float due to surface te shown in the figure Both the ring and have same radius What can you c about their masses thickness may be di 0 A B 1 Both have the same mass 2 Mass of the ring is half of that of 3 Mass of the ring is double to that of 4 More information is needed to

5 Alternating current cannot be measured by DC ammeter because becau 1 average value of current for complete cycle is zero 2 AC changes direction 3 AC cannot pass through DC ammeter 4 DC ammeter will be smaller than AC

32 Two sources of equal emf are connected in series to an external resistance R The internal resistances of both the sources are r and 1 such that r r If potential difference across the source having internal resistance r2 is zero then 1 RA 1 2 3 R 1 2 1 R 2 R r 1 4 R 1 1

13 Atmospheric pressure is 1 0x105 N m and the density of air is 1 29 kg m If the density of air is constant as you get higher and higher the height of the atmosphere needed to produce this pressure is A 77000 m O B 10300 m O C 7900 m O D 1200 m

Sir but answer is given as first how as you are stating its answer third 4 0 4 second Which one of the following graphs represents correctly the given wave equation at origin K 2 3 1 0 0 2 1S id tak m 2 3 N F 2 3 0 0 3 2 3 133 2 3 3 3 0 0 2 3 2 3 una y 2 3 sin 2rx 3mt 3 0 0 2 3 t N

A leaky capacitor Ze 74 5 2 is in series with a coil Z 40 22 and a resistor R 56 2 When a voltage V 200 V is applied I 2 5 A and the p d across R and Z combined is 194 V Find the los in the capacitor Ans 24 3 W

A playground merry go round of radius 1 5 m has a mass 20 kg with the shape of solid cylinder and is rotating at 10 rev min about its center of mass A 30 kg child hops onto the merry go round and manages to sit down on the edge Determine the new angular speed of the system

an obtuse angle The graph between terminal velocity along y axis and square of radius along x axis of spherical body of density p allowed to fal through a fluid of density o is a 1 Straight line with positive slope 2 Straight line with negative slope 3 Straight line perpendicular to x axis 4 Straight line perpendicular to y axis

3 4 will fly up When water droplets merge to form a bigger 38 drop down on the floor of the hall 1 Energy is liberated 2 Energy is absorbed 3 Energy is neither liberated nor absorbed 4 Energy may either be liberated or absorbe donending on the nature of the liquid

34 A given sample of Na2SO4 contains 6 02 x 1022 SO4 ions Calculate i number of Na ions ii number of formula units and iii weight of the sample Ans i 1 204 x 1024 Na ions ii 6 02 x 1022 formula units iii 14 2 g

ose the confect potentiometer arrangement is shown in the figure r A 1 R R 2 X wis J Driving cell has emf and internal resistance r Resistance of potentiometer wire AB is R X is the E cell of emf and internal resistance Balance point J can be obtained for all finite values of 3 B 2 R

om In the figure given below the acceleration of block P is ap 15i 15 under the action of external force Then acceleration of wedge Q is P always remain in contact with Q AY 1 6i 3 10 37 Q 2 15 4 5i X ET