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In thermodynamics, heat and work are:

In thermodynamics, heat and work are: a. Intensive thermodynamics state variables b. Extensive thermodynamics state variables c. Path functions d.... View Article

An RC circuit as shown in the figure

An RC circuit as shown in the figure is driven by an AC source generating a square wave. The output... View Article

A block of 200 g mass moves with a uniform speed in a horizontal circular groove, with vertical sidewalls of a radius of 20 cm. If the block takes 40 s to complete one round, the normal force by the sidewalls of the groove is:

a. 6.28 ×10–3 N b. 0.0314 N c. 9.859×10–2 N d. 9.859×10–4 N Answer: (d) Normal force will provide the... View Article

The maximum and minimum distances of a comet from the Sun are 1.6×10¹² m and 8.0×10¹⁰m respectively. If the speed of the comet at the nearest point is 6×10⁴ ms^–1, the speed at the farthest point is :

a. 1.5×103 m/s b. 4.5×103 m/s c. 3.0×103 m/s d. 6.0×103 m/s Answer: (c) Let point 1 is nearest point,... View Article

A plane electromagnetic wave of frequency 500 MHz is travelling in vacuum along y-direction. At a particular point in space and time,[latex]vec{B}=8.0times 10^{-8}hat{z}T[/latex]. The value of electric field at this point is: (speed of light = 3×10⁸ ms^–1) Assume x, y, z are unit vectors along [latex]hat{x}[/latex], [latex]hat{y}[/latex] and [latex]hat{z}[/latex] directions.

a. \(\begin{array}{l}2.6\hat{x}\frac{V}{m}\end{array} \) b. \(\begin{array}{l}-2.6\hat{y}\frac{V}{m}\end{array} \) c.\(\begin{array}{l}24\hat{x}\frac{V}{m}\end{array} \) d.\(\begin{array}{l}-24\hat{x}\frac{V}{m}\end{array} \) Answer: (d) E0 = B⋅C E0 = (8×10–8) × (3×108)... View Article

One main scale division of a vernier callipers is ‘a’ cm and n^th division of the vernier scale coincides with (n–1)^th division of the main scale. The least count of the callipers in mm is:

a.\(\begin{array}{l}\left ( \frac{n-1}{10n} \right )a\end{array} \) b.10a/n c.10na/(n-1) d. 10a/(n-1) Answer: (b) MSD → Main scale division VSD → Vernier... View Article

The stopping potential in the context of the photoelectric effect depends on the following property of incident electromagnetic radiation:

a. Amplitude b. Phase c. Frequency d. Intensity Answer: (c) According to Einstein’s photoelectric equation, stopping potential depends on frequency... View Article

Four equal masses, m each is placed at the corners of a square of length(l) as shown in the figure. The moment of inertia of the system about an axis passing through A and parallel to DB would be:

Four equal masses, m each is placed at the corners of a square of length(l) as shown in the figure.... View Article

A block of mass m slides along a floor while a force of magnitude F is applied to it at an angle θ as shown in the figure. The coefficient of kinetic friction is μ_K. Then, the block’s acceleration ‘a’ is given by (g is the acceleration due to gravity)

a. \(\begin{array}{l}\frac{F}{m}cos\theta -\mu _{k}(g-\frac{F}{m}sin\theta )\end{array} \) b.\(\begin{array}{l}\frac{F}{m}cos\theta -\mu _{k}(g+\frac{F}{m}sin\theta )\end{array} \) c. \(\begin{array}{l}\frac{F}{m}cos\theta +\mu _{k}(g-\frac{F}{m}sin\theta )\end{array} \) d.\(\begin{array}{l}-\frac{F}{m}cos\theta -\mu _{k}(g-\frac{F}{m}sin\theta... View Article

A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be:

a. 200 b. 400 c. 100 d. 300 Answer: (c) Given that, the height of the peak of the antenna:... View Article

The number of octahedral voids per lattice site in a lattice is __________.(Rounded off to the nearest integer)

Answer: 1 Assuming FCC No of lattice sites = 6 face centre + 8 corner = 14 No. of octahedral... View Article

The pH of ammonium phosphate solution, if pk_a of phosphoric acid and pk_b of ammonium hydroxide are 5.23 and 4.75 respectively, is_____________.

Answer: 7 \(\begin{array}{l}\left ( NH_{4} \right )_{3}PO_{4}\leftrightharpoons 3NH_{4}^{+} + PO_{4}^{3-}\end{array} \) \(\begin{array}{l}[H^{+}] = K_{a}\times \sqrt{\frac{kw}{k_{a}\times k_{b}}}\end{array} \) pH = pka... View Article

If the activation energy of a reaction is 80.9 kJ mol^–1

If the activation energy of a reaction is 80.9 kJ mol–1, the fraction of molecules at 700K, having enough energy... View Article

In a mildly alkaline medium, thiosulphate ion is oxidized by to “A”. The oxidation state of sulphur in “A” is ________.

Answer: +6 S2O2-3 + MnO–4 Alkaline Medium →A A → SO2-4 Oxidation no. of ‘S’ = +6

A ball weighing 10g is moving with a velocity of 90ms^-1. If the uncertainty in its velocity is 5%, then the uncertainty in its position is ________×10^-33m.

[Given: h = 6.63×10-34 J s] Answer: 1 m = 10 g = 10-2 kg v = 90 m/s Δv... View Article

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