Physics Test - ...

From Brewster's law of polarisation, it follows that the angle of polarisation depends upon:

A Proton and an alpha particle both are accelerated through the same potential difference. The ratio of corresponding de-Broglie wavelengths is:

If applied torque on a system is zero, i.e., τ = 0, then for that system:

The electric field intensity E, current density J and specific resistance k are related to each other through the relation:

In an experiment, brass and steel wires of length 1 m each with areas of cross\(1 mm ^2\) sectionare used. The wires are connected in series and one end of the combined wire isconnected to a rigid support and other end is subjected to elongation. The stressrequires to produced a new elongation of 0.2 mm is:

[Given, the Young’s Modulus for steel and brass are respectively\(120 \times 10^9 N / m ^2\) and 60\(\left.\times 10^9 N / m ^2\right]\)

What should be increased to increase the angular magnification of a simple microscope?

n mole a perfect gas undergoes a cyclic process \(\mathrm{ABCA}\) (see (figure) consisting of the following processes.

\(\mathrm{A} \rightarrow \mathrm{B}\) : Isothermal expansion at temperature \(\mathrm{T}\) so that the volume is doubled from \(\mathrm{V}_1\) to \(\mathrm{V}_2=2 \mathrm{~V}_1\) and pressure changes from \(\mathrm{P}_1\) to \(\mathrm{P}_2\).

\(B \rightarrow C\) : Isobaric compression at pressure \(P_2\) to initial volume \(V_1\).

\(\mathrm{C} \rightarrow \mathrm{A}\) : Isochoric change leading to change of pressure from \(\mathrm{P}_2\) to \(\mathrm{P}_1\).

Total work done in the complete cycle \(\mathrm{ABCA}\) is:

A thin lens made of glass (refractive index \(=1.5\) ) of focal length \(f\) \(=16 \mathrm{~cm}\) is immersed in a liquid of refractive index 1.42 . If its focal length in liquid is \(\mathrm{f}_1\), then the ratio \(\mathrm{f}_1 / \mathrm{f}\) is closest to the integer:

A rod of mass ‘M’ and length ‘2L’ is suspended at its middle by a wire. It exhibits torsional oscillations; If two masses each of ‘m’ are attached at distance ‘\(\frac{L}{2}\)’ from its centre on both sides, it reduces the oscillation frequency by 20%. The value of ratio m/M is close to:

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads \(49 \mathrm{~N}\), when the lift is stationary. If the lift moves downward with an acceleration of \(5 \mathrm{~m} / \mathrm{s}^{2}\), the reading of the spring balance will be: