Science (English Medium) Class 11 - CBSE Question Bank Solutions for Physics

A steel wire of cross-sectional area 0.5 mm² is held between two fixed supports. If the wire is just taut at 20°C, determine the tension when the temperature falls to 0°C. Coefficient of linear expansion of steel is 1.2 × 10^–5 °C^–1 and its Young's modulus is 2.0 × 10^–11 Nm^–2.

A steel ball that is initially at a pressure of 1.0 × 10⁵ Pa is heated from 20°C to 120°C, keeping its volume constant.
Find the pressure inside the ball. Coefficient of linear expansion of steel = 12 × 10^–6 °C^–1and bulk modulus of steel = 1.6 × 10¹¹ Nm^–2.

A uniform tube closed at one end, contains a pellet of mercury 10 cm long. When the tube is kept vertically with the closed-end upward, the length of the air column trapped is 20 cm. Find the length of the air column trapped when the tube is inverted so that the closed-end goes down. Atmospheric pressure = 75 cm of mercury.

The ratio C_p / C_v for a gas is 1.29. What is the degree of freedom of the molecules of this gas?

Work done by a sample of an ideal gas in a process A is double the work done in another process B. The temperature rises through the same amount in the two processes. If C_Aand C_B be the molar heat capacities for the two processes,

For a solid with a small expansion coefficient,

  The value of C_p − C_v is 1.00 R for a gas sample in state A and 1.08 R in state B. Let p_Aand p_B denote the pressures and T_A and T_B denote the temperatures of the states A and B, respectively. It is most likely that

Let C_v and C_p denote the molar heat capacities of an ideal gas at constant volume and constant pressure respectively. Which of the following is a universal constant?

70 calories of heat are required to raise the temperature of 2 mole of an ideal gas at constant pressure from 30° C to 35° C. The amount of heat required to raise the temperature of the same gas through the same range at constant volume is

The figure shows a process on a gas in which pressure and volume both change. The molar heat capacity for this process is C.

The molar heat capacity for the process shown in the figure is

The molar heat capacity of oxygen gas at STP is nearly 2.5 R. As the temperature is increased, it gradually increases and approaches 3.5 R. The most appropriate reason for this behaviour is that at high temperatures

A sample of an ideal gas (γ = 1.5) is compressed adiabatically from a volume of 150 cm³ to 50 cm³. The initial pressure and the initial temperature are 150 kPa and 300 K. Find (a) the number of moles of the gas in the sample (b) the molar heat capacity at constant volume (c) the final pressure and temperature (d) the work done by the gas in the process and (e) the change in internal energy of the gas.

Which of the following example represent periodic motion?

A swimmer completing one (return) trip from one bank of a river to the other and back.

Which of the following example represent periodic motion?

A freely suspended bar magnet displaced from its N-S direction and released.

Which of the following example represent periodic motion?

A hydrogen molecule rotating about its center of mass.

Which of the following example represent (nearly) simple harmonic motion and which represent periodic but not simple harmonic motion?

The rotation of the earth about its axis.

Which of the following example represent (nearly) simple harmonic motion and which represent periodic but not simple harmonic motion?

A motion of an oscillating mercury column in a U-tube.

Which of the following example represent (nearly) simple harmonic motion and which represent periodic but not simple harmonic motion?

The motion of a ball bearing inside a smooth curved bowl, when released from a point slightly above the lowermost point.

Given below are some functions of x and t to represent the displacement (transverse or longitudinal) of an elastic wave. State which of these represent (i) a traveling wave, (ii) a stationary wave or (iii) none at all:

y = 2 cos (3x) sin (10t)