A rectangular copper coil is placed in a uniform magnetic field of induction 40 mT with its plane perpendicular to the field. The area of the coil is shrinking at a constant rate of 0.5 […]
Light is emitted when
Options
(a) Electron make an transition from higher orbit to lower orbit (b) Electron make an transition from lower to higher orbit (c) Electron rotates in its own orbit […]
When photons of energy hν fall on an aluminium plate (of work function E₀), photoelectrons of maximum kinetic energy K are ejected. If the frequency of radiation is doubled, the maximum kinetic energy of the […]
Cathode rays are produced when the pressure is of the order of
Options
(a) 2 cm of Hg (b) 0.1 cm of Hg (c) 0.01 mm of Hg (d) 1μm of Hg
Correct […]
A battery of e.m.f. E and internal resistance r is connected to an external resistance R the condition for maximum power transfer is
Options
(a) rR (c) r=1/R (d) r=R
Correct Answer:
r=R
A galvanometer having internal resistance 10Ω requires 0.01 A for a full scale deflection. To convert this galvanometer to a voltmeter of full scale deflection at 120V, we need to connect a resistance of
Ratio of longest wavelengths corresponding to Lyman and Balmer series in hydrogen spectrum is
Options
(a) (5/27) (b) (3/23) (c) (7/29) (d) (9/31)
Correct Answer:
(5/27)
Explanation:
No explanation available. Be the first […]
A nuclear reaction is given as 4 ₁H¹→₂He⁴+₀e¹+energy Mention the type of reaction.
Options
(a) fusion (b) fission (c) just a chemical reaction (d) None of these
Correct Answer:
fusion
Explanation:
No explanation […]
A L-C-R circuit with L=1.00 mH, C=10μF and R=50Ω, is driven with 5 V AC voltage. At resonance, the current through the circuit is
Options
(a) 0.2 A (b) 0.25 A (c) 0.15 […]
The difference in the lengths of a mean solar day and a sidereal day is about
Options
(a) 1 min (b) 4 min (c) 15 min (d) 56 min
Correct Answer:
56 min
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