Physics

While measuring the unknown resistance the help of slide wire bridge a greatest accuracy can be achieved when__________________?

Options:

• A. a most sensitive galvanometer is used
• B. a steady voltage cell is used
• C. the balance point is close to the middle of the wire
• D. a high resistance box is used in one of its gap

View Answer

C. the balance point is close to the middle of the wire

Electromagnetic waves transport___________________?

Options:

• A. Energy
• B. Momentum
• C. Mass
• D. Heat

View Answer

A. Energy

An ammeter measures the total current flowing through a circuit when it is connected__________________?

Options:

• A. in series with the circuit
• B. in parallel with circuit
• C. in series with any of the parallel resistances in the circuit
• D. in parallel with any of the series resistances in the circuit

View Answer

A. in series with the circuit

Electromagnetic waves emitted from antenna are________________?

Options:

• A. Stationary
• B. Longitudinal
• C. Transverse
• D. All the above

View Answer

C. Transverse

The effective way to increase the sensitivity of a moving coil galvanometer is to___________________?

Options:

• A. use a very long and fine suspension
• B. use a coil of very large area
• C. use a coil with very large number of turns
• D. use a very strong magnetic field

View Answer

D. use a very strong magnetic field

A capacitor of capacitance 30

Options:

• A. 0.9sec
• B. 15 sec
• C. 1.5x105sec
• D. 0.9x102sec

View Answer

A. 0.9sec

When an electron moving with a uniform speed in a vacuum enters a magnetic field in a direction perpendicular to the field the subsequent path of the electron is ___________________?

Options:

• A. a straight line parallel to the field
• B. a parabola in a plane perpendicular to the field
• C. a circle in a plane perpendicular to the field
• D. a straight line along its initial direction

View Answer

C. a circle in a plane perpendicular to the field

To find the r.m.s value of an alternating current mathematically we need to have ________________?

Options:

• A. Mean value of I2
• B. Square root of mean value of I2
• C. Square root of I2
• D. Square of 1/2

View Answer

B. Square root of mean value of I2

Galvanometer is a very sensitive device with______________________?

Options:

• A. very low damping
• B. very high damping
• C. no damping at all
• D. radial field disintegration

View Answer

A. very low damping

An alternating current is represented by the equation I = I?sin?t which of the following equation represents an alternating current of frequency and amplitude twice that of the above current ?

Options:

• A. I = 2I?Sin(?t/2)
• B. I = 2I?Sin(2?t)
• C. I = 2ISin?t
• D. I = I?sin(2?t)

View Answer

B. I = 2I?Sin(2?t)