Class 11 Physics Model Question Set D

The dimensional formula of gravitational constant is:

a.

b.

c.

d.

Two equal vectors of magnitude 10 N act at an angle of . Their resultant is:

a. 5 N

b. 10 N

c. 15 N

d. 20 N

The velocity-time graph of a moving body is shown below.

Velocity-time graph What does the slope of this graph represent?

a. Displacement

b. Acceleration

c. Momentum

d. Force

A body of mass 4 kg is moving with an acceleration of 3   𝑚 / 𝑠 2 3m/s 2 . The net force acting on it is:

a. 7 N

b. 12 N

c. 16 N

d. 24 N

A spring of force constant 200 N/m is compressed by 0.1 m. The elastic potential energy stored is:

a. 0.5 J

b. 1 J

c. 2 J

d. 4 J

The orbital speed of a satellite revolving around the Earth depends on:

a. Mass of satellite only

b. Radius of orbit and mass of Earth

c. Mass of satellite and its speed

d. Shape of satellite

The SI unit of Young's modulus is:

a. N

b. N/m

c. N/m²

d. J

A temperature of on the Celsius scale is equal to:

a. 273 K

b. 300 K

c. 310 K

d. 327 K

A metal rod of length 2 m has a coefficient of linear expansion . If its temperature increases by 10 K, its increase in length is:

a. 0.03 mm

b. 0.3 mm

c. 3 mm

d. 30 mm

A convex lens produces a real image of an object placed beyond 2 𝐹 2F. The image is formed:

a. Between F and 2F

b. At 2F

c. Beyond 2F

d. At infinity

The half-life of a radioactive substance is 5 days. The fraction remaining after 15 days is:

a. 1/2

b. 1/4

c. 1/8

d. 1/16

(a) State the principle of homogeneity of dimensions. [2]

(b) A displacement vector of 12 m acts along the positive X-axis and another displacement of 5 m acts along the positive Y-axis, as shown in the figure. Calculate the magnitude and direction of the resultant displacement. [3]

A motorbike starts from rest and accelerates uniformly at for 8 seconds.

(a) Calculate its final velocity. [2]

(b) Calculate the total distance travelled. [3]

A 2 kg stone is tied to a light string and rotated in a horizontal circle of radius 0.8 m at a speed of 4 m/s.

(a) Draw a labelled diagram showing the stone, radius and centripetal force. [2]

(b) Calculate the centripetal force acting on the stone. [2]

(c) What provides the centripetal force in this situation? [1]

(a) State the law of conservation of mechanical energy. [1]

(b) A ball of mass 2 kg is dropped from a height of 20 m. Neglecting air resistance, calculate its velocity just before striking the ground. Take . [2]

(c) What happens to the gravitational potential energy during its fall? [2]

A steel wire of length 2 m and cross-sectional area is stretched by a force of 100 N. If Young's modulus of steel is :

(a) Define Young's modulus. [2]

(b) Calculate the extension produced in the wire. [3]

The following figure represents a gas enclosed in a cylinder fitted with a movable piston.

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

(b) A gas absorbs 600 J of heat and performs 250 J of work. Calculate the increase in its internal energy. [2]

(c) What is an isothermal process? [1]

(a) Differentiate between transverse and longitudinal waves with one example each. [2]

(b) A sound wave travels through air with a velocity of 340 m/s and has a frequency of 170 Hz. Calculate its wavelength. [3]

The following diagram represents a light ray passing from air into glass.

(a) State Snell's law of refraction. [2]

(b) If the angle of incidence is and the angle of refraction is , calculate the refractive index of glass relative to air. [2]

(c) Define critical angle. [1]

A battery of emf 12 V and internal resistance 1 Ω is connected to an external resistance of 5 Ω.

(a) Draw a labelled circuit diagram. [1]

(b) Calculate the current flowing in the circuit. [2]

(c) Calculate the terminal potential difference of the battery. [2]

(a) Define work function of a metal. [1]

(b) Explain the photoelectric effect briefly. [2]

(c) Draw a labelled symbol of a p-n junction diode and state one application of it. [2]

A football is kicked from the ground with an initial velocity of 25 m/s at an angle of with the horizontal, as shown in the figure.

Taking , and :

(a) Resolve the initial velocity into horizontal and vertical components.

(b) Calculate the time of flight.

(c) Calculate the maximum height attained by the football.

(d) Calculate the horizontal range.

(a) Define coefficient of linear expansion.

(b) A brass rod of length 1.5 m is heated from to . If its coefficient of linear expansion is , calculate the increase in its length.

(c) A 0.5 kg metal block at is dropped into 1 kg of water at . The final temperature becomes . Calculate the specific heat capacity of the metal. Take the specific heat capacity of water as , neglecting heat loss.

(a) Define a thin lens.

(b) Draw a labelled ray diagram of a convex lens when the object is placed beyond .

(c) A double convex glass lens has refractive index 1.5 and radii of curvature and . Using the lens maker's formula, calculate its focal length in air.

(a) State Coulomb's law of electrostatic force.

(b) Two point charges of and are separated by a distance of 0.3 m in air. Calculate the magnitude of the electrostatic force between them. State whether the force is attractive or repulsive.

(c) Explain the principle of electromagnetic induction.

(d) A radioactive sample has an initial mass of 160 mg and a half-life of 4 hours. Calculate the mass remaining after 12 hours.