List of practice Questions

The energy diagram of a hydrogen atom is given below. Arrange the wavelengths corresponding to different emissions in increasing order.

The displacement current due to time varying electric field is given by

When someone punches a wall, there is no visible effect upon it. This example can be used to teach?
(1) Law of conservation of energy can be violated in specific cases 
(2) Law of conservation of energy can never be violated. 
(3) Sometimes energy is invisible and needs to be visualised. 
(4) Sometimes there is no effect of force on energy.

Two wires of copper have lengths L and 2L and cross sectional area 2A and A, respectively. The ratio of their specific resistance would be-

What is the self inductance of a solenoid of length 50 cm, if area of cross section is 10 cm² and total number of turns is 600?

Which of the following statement is not true for the electromagnetic waves?

Choose the correct formula for magnifying power of a simple microscope from the following

Which of the following statements are correct?
A. Number of photoelectrons emitted per second is directly proportional to the intensity of incident radiation
B. Cut off potential is the minimum negative potential given to the plate for which photocurrent becomes maximum
C. For a given frequency of the incident radiation, the stopping potential is independent of its intensity
D. Even for the exceedingly dim incident radiation apparent time lag is~ 109s or less
E. Photons are electrically neutral and are not deflected by electric and magnetic fields
Choose the correct answer from the options given below:

Two protons P and Q are placed between two charged plates A and B as shown, then

At what distance should an object be placed from a convex lens of focal length 15 cm to obtain a real image three times the size of the object?

The boiling point of water _______

The potential of a uniformly charged spherical shell at a point r/2 from its centre is 5 V. The potential at its surface is:
(Given radius of shell = r)

The magnitude of electric current is increasing from A towards B. If there is any induced current in the loop as shown in the figure, its direction will be:

Electron and Photon have same de Broglie wavelength, which of the following is true for their momentum:

Consider two different hydrogen atoms. The electron in each atom is in first excited state. According to Bohr's model, electrons will have:

A parallel beam of monochromatic light of wavelength 460 nm passes through a long slit of width 0.1 mm. What is the angular divergence in which most of the light is diffracted?

One light year is equals to______.

Three capacitors of capacitances 3 \(\mu\)F, 6 \(\mu\)F and 12 \(\mu\)F are connected in series. Find the potential difference across the 6 \(\mu\)F capacitor, if a battery of 7 V is connected across this combination:

The coercivity of a bar magnet is 140 A m\(^{-1}\). To demagnetize it, it is placed inside a solenoid of length 1.6 m and number of turns 112. What is the current flowing through the solenoid?

Magnetic field \(|B|\) at a point \(P\) in the following network is:

In an a.c. circuit, the rms voltage is \(100\sqrt{2}\) V. The peak value of voltage would be:

A spherical air lens of radii \( R_1 = R_2 = 10 \, \text{cm} \) is cut from a glass (\(\mu = 1.5\)) cylinder as shown in the figure. Its focal length is \( f_1 \). If a liquid of refractive index \( \mu_2 \) is filled in the space, then the focal length of the liquid lens becomes \( f_2 \). Calculate \( f_1 \) and \( f_2 \). Choose the correct options from the following.

Two point charges \(q\) and \(-3q\) are kept 12 cm apart. The distance of the point from \(q\) on the line between two charges at which potential due to this system of charges is zero will be:

A conducting sphere of radius R is given a charge Q. What is the electric field and the electric potential at the centre of the sphere?

Four identical capacitors each of capacitance C are arranged as shown in the figure. What is the effective capacitance between P and Q?