An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is
Options
(a) (E/2m)¹∕₂ (b) c(2mE)¹∕₂ (c) 1/c (2m/E)¹∕₂ (d) 1/c (E/2m)¹∕₂
Correct Answer: […]
Three resistances 2Ω, 3Ω and 4Ω are connected in parallel. The ratio of currents passing through them when a potential difference is applied across its ends will be
Options
(a) (5:4:3) (b) (6:3:2) […]
A metal plate weighing 750g is to be electroplated with 0.05% of its weight of silver. If a current of 0.8A is used, find the time (approx) needed for depositing the required weight of silver […]
A 1Ω resistance in series with an ammeter is balanced by 75 cm of potentiometer wire. A standard cell of emf 1.02 V is balanced by 50 cm. The ammeter shows a reading of 1.5A. […]
The wavelength of kα, X-rays produced by an X-ray tube 0.76Å. The atomic number of the anode material of the tube is
Options
(a) 20 (b) 60 (c) 41 (d) 80
Correct Answer:
41
According to Bohr model of hydrogen atom, only those orbits are permissible which satisfy the condition
Options
(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 galvanometer coil has a resistance of 15 ohm and gives full scale deflection for a current of 4 mA. To convert it to an ammeter of range 0 to 6 A,
Options
Which of the two have same dimensions?
Options
(a) Force and strain (b) Force and stress (c) Angular velocity and frequency (d) Energy and strain
Correct Answer:
Angular velocity and frequency
Explanation:
No […]
Unit of electrical conductivity is
Options
(a) Ω⁻¹ (b) Ω⁻¹ cm (c) Ω⁻¹ cm⁻² (d) Ω⁻¹ cm⁻¹
Correct Answer:
Ω⁻¹ cm⁻¹
Explanation:
No explanation available. Be the first to write the explanation for […]
A spring when stretched by 2mm containing energy 4 J. If it is stretched by 10 mm, its potential energy becomes equal to
Options
(a) 4 J (b) 54 J (c) 415 J (d) […]
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