Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 12

MEDIUM

NEET

IMPORTANT

Earn 100

The peak value of an alternating e.m.f given by $E = E_{0} \cos ω t,$ is $10 V$ and frequency is $50 Hz .$ At time $t = (\frac{1}{600}) \sec,$ the instantaneous value of e.m.f is:

50% studentsanswered this correctly

Important Questions on Alternating Current

EASY

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 13

An alternating voltage is given by,

e = e_{1} \sin ω t + e_{2} \cos ω t

. Then the root mean square value of voltage is given by :

EASY

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 14

An AC voltage is given by :

E = E_{0} \sin \frac{2 π t}{T}

. Then the mean value of voltage is calculated over time interval of

\frac{T}{2}

seconds:

EASY

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 15

The voltage of an AC source varies with time according to the equation,

V = 100 \sin 100 π t \cos 100 π t

where

t

is in second and

V

is in volt. Then:

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 16

An AC voltage of

V = 220 \sqrt{2} \sin (2 π 50 t + \frac{π}{2})

is applied across a DC voltmeter, its reading will be:

EASY

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 17

The RMS value of an AC of

50 H z

is

10 A

. The time taken by the alternating current in reaching from zero to maximum value and the peak value of current will be

EASY

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 18

If instantaneous current is given by

i = 4 \cos (ω t + ϕ)

amperes, then the rms value of current is -

EASY

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 19

A

40 Ω

electric heater is connected to a

200 V, 50 Hz

mains supply. The peak value of electric current flowing in the circuir is approximately

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 28 - Alternating Current>Exercise-1>Q 20

An AC ammeter is used to measure current in a circuit. When a given direct constant current passes through the circuit, the AC ammeter reads

3 A

. When an alternating current passes through the circuit, the AC ammeter reads

4 A

. Then the reading of this ammeter if DC and AC flow through the circuit simultaneously is,