High voltage transmission line is preferred as
(a) Its appliances are less costly
(b) Thin power cables are required
(c) Idle current very low
(d) Power loss is very less
(a) Its appliances are less costly
(b) Thin power cables are required
(c) Idle current very low
(d) Power loss is very less
(d) Power loss is very less
In an A.C. circuit, Irms and I₀ are related as
(a) Irms = p I₀
(b) Irms = 2 I₀
(c) Irms = I₀/p
(d) Irms =I₀ / 2
A capacitor of capacity C has reactance X. If capacitance and frequency become double then reactance will be
(a) 4X
(b) X/2
(c) X/4
(d) 2X
In electric arc furnace Cu or Iron is melted due to variation of
(a) current
(b) magnetic field
(c) voltage
(d) electric field
In highly inductive load circuit, it is more dangerous when
(a) we close the switch
(b) open the switch
(c) increasing the resistance
(d) decreasing the resistance
In series R-L-C circuit, quality factor can be improved by
(a) decreasing L
(b) increasing C
(c) decreasing R
(d) decreasing R & L
Show that in the free oscillations of an LC circuit, the sum of energies stored in the capacitor and the inductor is constant in time.
State which of the two a capacitor or an inductor, tends to become SHORT when the frequency of the applied alternating voltage has a high value.
When a soap bubble is given an electric charge
(A) It contracts
(B) It expands
(C) Its size remains the same
(D) It expands or contracts depending upon whether the charge is positive or negative
The figure below shows a potentiometer with a cell of 2.0 V and internal resistance 0.40 Ω maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.04 V (for very moderate currents up to a few mA) gives a balance point at 67.3 cm length of the wire. To ensure very low currents drawn from the standard cell, a very high resistance of 600 KΩ is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown emf Ꜫ and the balance point, found similarly, turns out to be at 82.3 cm length of the wire. What is the value Ꜫ?
(a) 0.25 V
(b) 2.25 V
(c) 3.25 V
(d) 1.25 V
Which among the following isn’t a suitable phenomenon to establish that light is wave motion?
a) Interference.
b) Diffraction.
c) Reflection.
d) Polarization.
The phenomena which is not explained by Huygen’s construction of wavefront
(a) reflection
(b) diffraction
(c) refraction
(d) origin of spectra
An unpolarised beam of intensity \(I_0\) is incident on a pair of nicols making angle of 60° with each other. The intensity of right emerging from the pair is
A Galvanometer of resistance 10 Ω gives full-scale deflection when 1 mA current passes through it. The resistance required to convert it into a voltmeter reading upto 2.5 Volt is;
a) 9800 Ω
b) 2490 Ω
c) 4980 Ω
d) 9880 Ω.
In a Young’s double slit experiment the distance between the slit is 1 mm and the distance of screen from the slit is 1 m. If light of wavelength 6000 A is used then the fringe width is:
(a) 0.4 mm
(b) 0.5 mm
(c) 0.6 mm
(d) 0.8 mm