The alternating current in a circuit is given by I=50 sin314t. The peak value and frequency of the current are
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(a) I₀=25 A and f=100 Hz (b) I₀=50 A and f=50 Hz (c) […]
A bar magnet of pole strength 10 A-m is cut into two equal parts breadthwise. The pole strength of each magnet is
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(a) 5 A-m (b) 10 A-m (c) 15 A-m (d) […]
If two slits in Young’s experiment are 0.4 mm apart and fringe width on a screen 200 cm away is 2 mm, the wavelength of light illuminating the slits is
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(a) 500 […]
A magnifying glass of focal length 5 cm is used to view an object by a person whose smallest distance of distinct vision is 25 cm. If he holds the glass close to eye, then […]
A 50Hz AC signal is applied in a circuit of inductance of (1/π)H and resistance 2100Ω. The impedance offered by the circuit is
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(a) 1500Ω (b) 1700Ω (c) 2102Ω (d) 2500Ω
Correct […]
According to Bohr model of hydrogen atom, only those orbits are permissible which satisfy the condition
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(a) mv=nh (b) mv²/r=n(h/2π) (c) mvr=n(h/2π) (d) mvr²=n(h/2π)
Correct Answer:
mvr=n(h/2π)
Explanation:
No explanation available. Be […]
A 1m long wire of diameter 0.31 mm has a resistance of 4.2Ω. If it is replaced by another wire of same material of length 1.5m and diameter 0.155 mm, then the resistance of wire […]
A hollow sphere of radius 0.1m has a charge of 5×10⁻⁸C. The potential at a distance of 5cm from the centre of the sphere is (1/4πε₀=9×10⁹NM²C⁻²)
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(a) 4000V (b) 4500V (c) 5000V […]
A conductor of length 5 cm is moved parallel to itself with a speed of 2 m/s, perpendicular to a uniform magnetic field of 10⁻³ Wb/m². The induced emf generated is
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(a) […]
24 cells of emf 1.5 V each having internal resistance of 1 ohm are connected to an external resistance of 1.5 ohms. To get maximum current,
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(a) all cells are connected in […]
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