List of top Physics Questions on thermal properties of matter asked in BITSAT

If the distance between an object and its two times magnified virtual image produced by a curved mirror is 15 cm, the focal length of the mirror must be:
In normal adjustment, for a refracting telescope, the distance between the objective and eyepiece is 30 cm. The focal length of the objective, when the angular magnification of the telescope is 2, will be:
Power of a biconvex lens is \( P \) diopter. When it is cut into two symmetrical halves by a plane containing the principal axis, the ratio of the power of two halves is:
An alternating voltage \( V(t) = 220 \sin 100\pi t \) volt is applied to a purely resistive load of \( 50\Omega \). The time taken for the current to rise from half of the peak value to the peak value is:
In an AC circuit, an inductor, a capacitor, and a resistor are connected in series with \( X_L = R = X_C \). The impedance of this circuit is:

Find the average value of the current shown graphically from \( t = 0 \) to \( t = 2 \) s. 
 

Five cells each of emf \(E\) and internal resistance \(r\) send the same amount of current through an external resistance \(R\) whether the cells are connected in parallel or in series. Then the ratio \(\frac{R}{r}\) is:
A wire of resistance \(160\Omega\) is melted and drawn into a wire of one-fourth of its length. The new resistance of the wire will be:
Electric potential at a point 'P' due to a point charge of \( 5 \times 10^{-9} \) C is 50 V. The distance of 'P' from the point charge is: (Assume, \( \frac{1}{4\pi\epsilon_0} = 9 \times 10^{9} \, {Nm}^2{C}^{-2} \))
The electric field at point (30, 30, 0) due to a charge of \(0.008 \, \mu{C}\) placed at the origin will be: (coordinates are in cm)
The speed of sound in oxygen at STP will be approximately:(Given, R = 8.3J\((K)^−1\), \(γ = 1.4)\)
The temperature of an ideal gas is increased from 200 K to 800 K. If the RMS speed of gas at 200 K is \( v_0 \), then the RMS speed of the gas at 800 K will be:
In a mixture of gases, the average number of degrees of freedom per molecule is 6. The RMS speed of the molecule of the gas is \( c \). Then the velocity of sound in the gas is:
On Celsius scale, the temperature of a body increases by \( 40^\circ C \). The increase in temperature on Fahrenheit scale is:
A source supplies heat to a system at the rate of \( 1000 W \). If the system performs work at the rate of \( 200 W \), the rate at which internal energy of the system increases is:
Young’s modulus of a material is \( Y \). If the length of a wire is doubled and the cross-sectional area is halved, then Young’s modulus will be:
With rise in temperature, the Young's modulus of elasticity:
The kinetic energy of a satellite in its orbit around Earth is \( E \). What should be the kinetic energy of the satellite to escape Earth's gravity?
A body which is initially at rest at a height \( R \) above the surface of the Earth of radius \( R \), falls freely towards the Earth. The velocity on reaching the surface of the Earth is:
A ball falling freely from a height of \( 4.9 \) m/s hits a horizontal surface. If \( e = \frac{3}{4} \), then the ball will hit the surface the second time after:
A person of mass \( 60 \) kg is inside a lift of mass \( 940 \) kg. The lift starts moving upwards with an acceleration of \( 1.0 \) m/s\( ^2 \). If \( g = 10 \) m/s\( ^2 \), the tension in the supporting cable is:
A body is thrown with a velocity of \( 9.8 \) m/s making an angle of \( 30^\circ \) with the horizontal. It will hit the ground after a time:
A radioactive material is reduced to \( \frac{1}{8} \) of its original amount in 3 days. If \( 8 \times 10^{-3} \) kg of the material is left after 5 days, what was the initial amount of the material?
Which of the following Maxwell's equations is valid for time varying conditions but not valid for static conditions:
Transverse waves of the same frequency are generated in two steel wires A and B. The diameter of A is twice that of B, and the tension in A is half that in B. The ratio of the velocities of the waves in A and B is: