Two concentric coils each of radius equal to 2π cm are placed at right angles to each other. If 3A and 4A are the currents flowing through the two coils, respectively. The magnetic induction (in […]
A cyclotron is used to accelerate
Options
(a) Only negatively charged particles (b) neutron (c) Both positively and negatively charged particles (d) Only positively charged particles
Correct Answer:
Only positively charged particles
Explanation: […]
A proton beam enters a magnetic field of 10⁻⁴ Wb/m² normally. If the specific charge of the proton is 10¹¹ C/kg and its velocity is 10⁹ m/s, then the radius of the circle described will […]
A person wants a real image of his own, 3 times enlarged. Where should he stand in front of a concave mirror of radius of curvature of 30 cm?
Options
(a) 90 cm (b) […]
Calculate the focal length of a reading glass of a person, if the distance of distinct vision is 75 cm
Options
(a) 75.2 cm (b) 25.6 cm (c) 100.4 cm (d) 37.5 cm
Correct […]
Core of electromagnets are made of ferromagnetic material which has
Options
(a) low permeability and high retentivity (b) high permeability and low retentivity (c) low permeability and low retentivity (d) high premeability and […]
To observed diffraction, the size of the obstacle
Options
(a) should be much larger than the wavelength (b) has no relation to wavelength (c) should be of the order of wavelength (d) should […]
A spherical shell of radius 10cm is carrying a charge q. If the electric potential at distance 5cm, 10cm and 15cm from the centre of the spherical shell is V₁,V₂ and V₃ respectively, then
A parallel plate capacitor is charged and then isolated. The effect of increasing the plate seperation on charge, potential and capacitance respectively are,
Options
(a) constant, decreases, increases (b) constant,decreases,decreases (c) constant, increases, […]
Pick out the statement which is incorrect?
Options
(a) A negative test charge experience a force opposite to the direction of the field (b) the tangent drawn to a line of force represents […]
2017 Copyright Doctor Dreams Training Academy