Round 15.5 to the nearest integer.
15.5 to the nearest integer is 16. The number 15.5 has two parts, such as the integer part and the... View Article
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If r1, r2, r3 be the radii of excircles of the triangle ABC then Σr1/√[Σr1r2] is equal to
(a) Σ Cot A/2 (b) Σ Cot A/2 Cot B/2 (c) Σ tan A/2 (d) Π tan A/2 Solution: Correct... View Article
What is the value of root 49?
The value of root 49 is 7. As we know the square root of 49 is a number which when... View Article
An infinite line charge of uniform electric charge density λ lies along the axis electrically conducting an infinite cylindrical shell of radius R. At time t=0, the space in the cylinder is filled with a material of permittivity ε and electrical conductivity σ. The electrical conduction in the material follows Ohm’s law. Which one of the following best describes the subsequent variation of the magnitude of current density j(t) at any point in the material?
a) b) c) d) Solution: Option d) describes the subsequent variation of the magnitude of current density j(t) at any... View Article
How to find a solid angle?
Solution: Solid angle is defined as a three dimensional angle subtended by any part of a spherical surface of unit... View Article
Find the forces in the hinged rods BC and AC, if AB = 60 cm, AC = 1.2 m, BC = 1.6 m (see figure). Hanging mass has a mass of
a) AC is in tension with force of 1000 N b) AC is in tension with force of 4000/3 N... View Article
Two blocks m1=300g and m2=500g are pushed by force F. If the coefficient of friction is 0.40. a) What must be the value of F if the blocks are to have an acceleration of [latex]200cm/s^{2}[/latex].
Solution: We know that \(\begin{array}{l}F_{G1}=F_{N1} and F_{G1}=F_{N1} and F_{G2}=F_{N2}\end{array} \) \(\begin{array}{l}\Sigma F_{x} = F – F_{1}-F_{2}=m_{T}a\end{array} \) \(\begin{array}{l}\Sigma F_{x} =... View Article
The phase relationship between current and voltage in a pure resistive circuit is best represented by.
a) b) c) d) Solution: The phase relationship between current and voltage in a pure resistive circuit is best represented by... View Article
Find the acceleration of a, b, c when the string between B and C is cut?
Solution For body C, T1-g=1*g Hence, T1=2g For body B, T2-T1-3g=2*3g T2=11g For body A, T3-T2-6g=3*6g T2=33g Instantaneous change in... View Article
When a piece of wire is held diametrically in a screw gauge [pitch =1mm, number of division on circular scale =100], the readings obtained are as shown. Now, if we measure the same with the help of vernier callipers [1MSD=1mm,10 divisions of vernier coinciding with 9 divisions of main scale] having a negative zero error of 0.5mm, then which of the following figures correctly represents the reading?
a) b) c) d) Solution: Option a) is the correct answer since the values match with the value of screw... View Article
Light of wavelength 4000 A˚ is incident on a metal surface. The maximum kinetic energy of emitted photoelectrons is 2 eV. What is the work function of the metal surface?
Einstein’s photoelectric equation for the work function of metal is given by : \(\begin{array}{l}\phi = \frac{hc}{\lambda}\end{array} \) \(\begin{array}{l}\phi = \frac{6.6*10^{-34}*3*10^{8}}{4000*10^{-10}}... View Article
In which of the following cases the center of mass of a rod is certainly not at its centre?
a) The density continuously increases from left to right. b) The density decreases from left to right up to the... View Article
A particle is thrown vertically upwards. The correct graph between its speed (v) and time (t) is given by (neglecting air resistance).
a) b) c) d) Solution: Option d) is the right answer. This graph explains that when the particle is moving... View Article
In the shown circuit the resistance R can be varied. In which of the option, the variation of the current i against R is correctly plotted?
a) b) c) d) Solution: C) is the right option. Applying Kirchoff’s law in the circuit we get, \(\begin{array}{l}I_{1}+I_{2}+I_{3}=0\end{array} \) \(\begin{array}{l}\frac{V-E}{r}+\frac{V-E}{r}+\frac{V-E}{r}=0\end{array}... View Article
Figure shows an arrangement of blocks, pulleys, and strings. Strings are massless and frictionless. The relation between acceleration of the blocks as shown in the figure is
A. a_{1}=6a_{2} B. a_{1}=3a_{2} C. a_{2}=6a_{1} D. a_{2}=3a_{1} Solution: C. a_{2}=6a_{1}
The switch in circuit shifts from 1 to 2 when Vc > 2V/3 and goes back to 1 from 2 when Vc < V/3. The voltmeter reads voltage as plotted. What is the period T of the wave from in terms of R and C?
a) RCln3 b) RC/2 ln3 c) 2RCln2 d) RC/3 ln3 Solution:a) RCln3
The circuit diagram shown here corresponds to the logic gate
a) AND b) OR c) NOR d) NAND Solution: c) NOR
For the given transistor circuit VBE = 0.7 V. Find I :- (1) 3.7 mA (2) 2.2 mA (3) 1.8 mA (4) 1.5 mA 54.
Given VBE = 0.7 V, S=0.7V, and I=2K\Omega I_{E}= \frac{4.3}{2*10^{3}} = 3.7 mA
In an adiabatic process [latex]1 m^{3}[/latex] of an ideal monatomic gas expands to [latex]8 m^{3}[/latex]. What is the ratio of final to initial temperature?
a) ¼ b) ⅛ c) 1 d) 8 Solution: b) ⅛
The magnitude of the gravitational field at distance r1 and r2 from the centre of a uniform sphere of radius R and mass M are F1 and F2 respectively, then
Solution: We know that \(\begin{array}{l}F=\frac{GM}{r^{2}}\end{array} \) If r\geq R \(\begin{array}{l}\frac{F1}{F2}=\frac{r2^{2}}{r1^{2}}\end{array} \) When r1≥R, r2≥R Again \(\begin{array}{l}F=\frac{GMr}{R^{2}}\end{array} \) When r≥R Force... View Article
