Class 11 Physics Model Question Set C

A vernier caliper has a least count of 0.01 cm. Its main scale reading is 2.4 cm and the 6th vernier division coincides with a main scale division. The measured length is:

a) 2.40 cm
b) 2.46 cm
c) 2.06 cm
d) 2.60 cm

A projectile is projected at an angle of 30° with horizontal velocity components as shown.

At the highest point, its:

a) Horizontal velocity is zero
b) Vertical velocity is zero
c) Both velocities are zero
d) Acceleration is zero

A body of mass 4 kg is moving in a circular path of radius 2 m with speed 6 m/s. Its centripetal force is:

a) 18 N
b) 36 N
c) 72 N
d) 144 N

The slope of a stress-strain graph within the elastic limit represents:

a) Pressure
b) Young's modulus
c) Density
d) Surface tension

A gas is heated at constant pressure. Which graph represents its volume against absolute temperature?

a) Horizontal line
b) Straight line passing through origin
c) Rectangular hyperbola
d) Vertical line

Two sound waves of frequencies 256 Hz and 260 Hz produce beats. Beat frequency is:

a) 2 Hz
b) 4 Hz
c) 516 Hz
d) 66,560 Hz

An object is placed at 2F of a convex lens. The image formed is:

a) Virtual and enlarged
b) Real and diminished
c) Real, inverted and same size
d) Virtual and erect

Three resistors of 2 Ω, 3 Ω and 6 Ω are connected in parallel. Their equivalent resistance is:

a) 11 Ω
b) 6 Ω
c) 1 Ω
d) 2 Ω

The SI unit of magnetic flux is:

a) Tesla
b) Weber
c) Henry
d) Ampere

A capacitor of capacitance 5 μF is charged to 100 V. The charge stored is:

a) 50 μC
b) 500 μC
c) 5 μC
d) 0.05 μC

The energy of a photon is directly proportional to its:

a) Wavelength
b) Amplitude
c) Frequency
d) Speed in vacuum

a) State the principle of conservation of linear momentum. [1]

b) A bullet of mass 20 g is fired horizontally at 300 m/s from a gun of mass 4 kg. Calculate the recoil velocity of the gun. [3]

c) Why does the gun recoil?[1]

A 0.5 kg stone is attached to a string of length 1.2 m and rotated in a horizontal circle with speed 4 m/s.

a) Define centripetal acceleration. [1]

b) Calculate the centripetal acceleration and centripetal force. [2]

c) What happens to centripetal force if the speed is doubled? [2]

A copper block of mass 2 kg is heated from 20°C to 80°C. Specific heat capacity of copper is 400 J kg⁻¹ K⁻¹.

a) Define specific heat capacity. [1]

b) Calculate the heat supplied to the block. [2]

c) Why is water used as a coolant in automobile engines? [2]

A gas occupies 400 cm³ at 300 K. Its pressure remains constant while it is heated to 450 K.

a) State Charles' law. [1]

b) Calculate its final volume. [2]

c) Draw a V-T graph for this process. [2]

A convex lens of focal length 20 cm forms an image of an object placed 30 cm in front of it.

a) Define focal length of a convex lens. [1]

b) Calculate the image distance using the lens formula. [2]

c) Calculate the magnification and state the nature of the image. [2]

Three resistors are connected as shown below.

a) Define equivalent resistance. [1]

b) Calculate the equivalent resistance of the circuit if 4 Ω and 6 Ω are in parallel and their combination is in series with 2 Ω. [2]

c) Calculate the total current when connected to a 12 V battery. [2]

A straight wire of length 0.4 m carrying a current of 5 A is placed perpendicular to a uniform magnetic field of 0.2 T.

a) State Fleming's left-hand rule. [1]

b) Calculate the magnetic force acting on the wire. [2]

c) What happens to the force if the wire is placed parallel to the magnetic field? [2]

A radioactive sample initially contains unstable nuclei. Its half-life is 5 days.

a) Define half-life. [1]

b) Calculate the number of undecayed nuclei after 15 days. [2]

c) Mention two applications of radioactivity. [2]

a) Derive an expression for the combined focal length when two thin lenses are combined coaxially. [3]

b) Write lens maker’s formula. [2]

c) An achromatic convergent lens is made up of two lenses in contact and the focal length of the combination is 30 cm. If the dispersive power of one is double that of the other, find the focal lengths of each lens. [1]

a) Derive lens maker's formula for a thin lens.[3]

b) For an equi-convex lens of focal length , find the radii of curvature of the two surfaces of the lens. [2]

A ball is projected from ground level with an initial velocity of 25 m/s at an angle of 37° to the horizontal. Neglect air resistance. Take , , and .

a) Resolve the initial velocity into horizontal and vertical components. [2]

b) Calculate the time of flight. [2]

c) Calculate the maximum height reached by the ball. [2]

d) Calculate the horizontal range of the projectile. [2]

A gas is enclosed in a cylinder fitted with a movable frictionless piston. It absorbs 800 J of heat and performs 300 J of work on its surroundings.

a) State the first law of thermodynamics. [2]

b) Calculate the change in internal energy of the gas. [2]

c) If the gas is compressed and 200 J of work is done on it while 100 J of heat is released, calculate its change in internal energy. [2]

d) Explain why the internal energy of an ideal gas depends only on temperature. [2]

a) Define a geostationary satellite. [1]

b) An artificial satellite of mass 1000 kg is moving in a circular orbit around the Earth, as shown in the figure. The radius of the Earth is 6400 km, the acceleration due to gravity is 10 m/s², and the height of the satellite above the Earth's surface is 800 km. Calculate:

i) The orbital velocity of the satellite (). [2]

ii) The time required by the satellite to complete one revolution around the Earth. [2]

iii) The total energy of the satellite in its orbit. [2]

c) Why does a person inside an artificial satellite revolving around the Earth experience weightlessness? [1]

Three capacitors of capacitances 2 μF, 3 μF and 6 μF are connected in a circuit. The 3 μF and 6 μF capacitors are in parallel, and this parallel combination is connected in series with the 2 μF capacitor. The circuit is connected to a 12 V battery.

a) Define capacitance and write its SI unit. [2]

b) Calculate the equivalent capacitance of the circuit. [2]

c) Calculate the total charge supplied by the battery. [2]

d) Calculate the potential difference across the 2 μF capacitor. [2]